Avatar photoKathy Marinias RN

Kathy Marinias is a Registered Nurse with more than 25 years of experience across cardiovascular health, nursing, and healthcare administration. Her career has been defined by a deep commitment to person-centred care — meeting patients where they are and walking alongside them through what can often be an overwhelming experience. Kathy brings a compassionate and practical perspective to heart health, with a particular gift for translating complex medical information into guidance that is meaningful, accessible, and genuinely empowering for patients and their families. As Associate Editor at Heart Matters, Kathy plays a central role in shaping the voice and direction of the platform — ensuring every article meets the standard our readers deserve. Her clinical experience and patient advocacy lens mean that nothing leaves Heart Matters without the patient perspective firmly at its heart.

Furosemide (Frusemide) Explained

furosemide, frusemide

Key Points

  • Furosemide is a powerful diuretic, a water or fluid tablet, used to remove excess fluid from the body in conditions such as heart failure, kidney disease and liver disease.
  • It works quickly and effectively, and is one of the most widely prescribed medications in cardiovascular medicine.
  • The most noticeable effect is a significant increase in urine output, which is the intended action of the medication.
  • Furosemide is typically taken in the morning, and sometimes again at midday if a second dose is needed. Taking it too late in the day can cause disruptive overnight urination.
  • The dose varies considerably between individuals. Some people need small doses while others require much larger amounts to achieve the same effect.
  • Regular monitoring of kidney function and electrolytes is an important part of long term furosemide use.

If you have been prescribed furosemide, you are in very good company. It is one of the most commonly used medications in cardiology and general medicine, and for good reason. It is highly effective at doing something that is genuinely important for many heart conditions: removing excess fluid from the body.

This article explains what furosemide is, why it is prescribed, what to expect when taking it, and what patients often find most surprising about this medication.

What Is Furosemide?

Furosemide is a diuretic, commonly known as a water or fluid tablet. It works by acting on the kidneys, specifically on a part of the kidney called the loop of Henle, which is why furosemide and medications like it are also called loop diuretics.

Its job is to tell the kidneys to excrete more salt and water into the urine than they otherwise would. The result is a significant increase in urine output, which reduces the total amount of fluid in the body. This is not a side effect, it is the intended action of the medication.

How furosemide works in the kidney, a three step diagram showing sodium, potassium and water being blocked from reabsorption and passing into urine
How furosemide works in the kidney tubule

Why Is It Prescribed?

Furosemide is prescribed whenever excess fluid has accumulated in the body and needs to be removed. This most commonly occurs in:

Heart failure. When the heart is not pumping as efficiently as it should, fluid can back up and accumulate in the lungs, the abdomen, and the legs. This congestion causes breathlessness, swollen ankles, and fatigue. Furosemide is a cornerstone of heart failure treatment because it directly addresses this fluid overload.

Kidney disease. Damaged kidneys do not excrete fluid as effectively, leading to fluid retention that furosemide can help manage.

Liver disease. Liver conditions such as cirrhosis can cause large amounts of fluid to accumulate in the abdomen, a condition called ascites. Furosemide is often used alongside another diuretic called spironolactone in this setting.

High blood pressure. Furosemide is occasionally used for blood pressure control, though other medications are more commonly chosen for this purpose.

Names Around the World

Furosemide is known by a number of different names depending on where you are and whether you are taking the generic or a branded version.

Generic name. Furosemide is the name used in Australia, the United Kingdom, the United States, Europe and most of the world. In some countries, and on older Australian and British prescriptions, it may be spelled frusemide. Both refer to exactly the same medication.

Common brand names include:

  • Lasix, the most widely recognised brand globally, used in Australia, the United States, the United Kingdom and many other countries
  • Frusid, used in Australia
  • Uremide, available in Australia
  • Frusehexal, available in Australia
  • Diural, used in some European countries
  • Seguril, used in Spain
  • Lasilix, used in France

Furosemide or Frusemide? They Are the Same Medication

If your doctor says frusemide, your old prescription says frusemide, or you have always known it by that name, you are not mistaken. Frusemide was the official approved name in Australia, the United Kingdom and most Commonwealth countries when the medication was first introduced in the 1960s.

In 2003 the United Kingdom and Australia officially adopted the international name furosemide, in line with the World Health Organization. Changing what an entire generation of clinicians had been saying and writing for decades takes considerably longer than a regulatory update, and you will hear both names used interchangeably in hospitals and clinics to this day.

If you travel internationally and need to continue your medication, the generic name furosemide will be understood by pharmacists in most countries, even if the brand name differs.

Available Formulations and Doses

Furosemide is available in several different forms, each suited to different clinical situations.

Tablets are the most commonly prescribed form for ongoing outpatient treatment. The standard tablet strengths available in Australia include:

  • 20mg, often used as a starting dose or for mild fluid retention
  • 40mg, the most commonly prescribed strength for heart failure and fluid management
  • 500mg, a high strength tablet sometimes known as Lasix 500. This strength is generally reserved for patients with advanced heart failure, significant diuretic resistance, or severe kidney disease, and is typically prescribed under the guidance of a cardiologist, heart failure specialist or nephrologist. It is not a first line dose and requires careful monitoring of kidney function and electrolytes.

Oral liquid preparations are available for patients who have difficulty swallowing tablets or who need a dose that falls between standard tablet strengths.

Intravenous and intramuscular injections are used in hospital settings when rapid or potent diuresis is needed. When someone is admitted with acute heart failure or severe fluid overload, furosemide given directly into a vein works within minutes and produces a much more immediate and powerful effect than the oral tablet. In hospital, furosemide can also be given as a continuous infusion through a drip when very large amounts of fluid need to be removed over a sustained period.

What to Expect When You Take It

The most immediate and noticeable effect of furosemide is a substantial increase in urination. This typically begins within 30 to 60 minutes of taking the medication and can produce a large volume of urine over several hours. For patients who are significantly fluid overloaded when they first start furosemide, the volume of urine produced can be quite striking.

This increase in urinary frequency and volume is not a problem. It is the medication working exactly as intended. The medical term for the passage of abnormally large volumes of urine is polyuria, and it is an expected feature of diuretic therapy, particularly in the early stages of treatment or after a dose increase.

As the excess fluid is removed from the body over days to weeks, the degree of diuresis typically settles to a more manageable level while the medication continues to prevent fluid from reaccumulating.

When to Take Furosemide

Timing matters with furosemide. Because the medication produces its diuretic effect within an hour of being taken, most doctors prescribe it to be taken in the morning. This way the period of increased urination occurs during waking hours rather than disrupting sleep.

When a larger total daily dose is needed, a second dose is typically prescribed at midday rather than in the afternoon or evening. Taking furosemide too late in the day means its peak diuretic effect will occur in the evening or overnight, which can significantly disrupt sleep with repeated trips to the bathroom.

If you are prescribed furosemide twice daily and find your sleep is being disrupted, it is worth discussing the timing of your second dose with your doctor. A simple adjustment in timing can make a considerable difference to quality of life without changing the total dose.

Why Doses Vary So Much Between Individuals

One of the things that surprises many patients is the wide range of doses that different people need. Furosemide doses can range from as little as 20 milligrams once daily to several hundred milligrams per day in some patients.

20mg → 500mg+
The range of daily furosemide doses used in clinical practice. The dose that is right for you depends on your kidney function, the severity of fluid overload, and how your body responds.

The reason for this variation is not simply about the severity of the underlying condition. Some people have what is called diuretic resistance, where the kidneys respond less efficiently to furosemide. This can occur in people with impaired kidney function, in those who have been on diuretics for a long time, and in some other clinical situations.

In these cases, larger doses are needed to achieve the same degree of fluid removal that a much smaller dose would produce in someone without resistance.

This is also why furosemide doses are sometimes changed over time. A dose that was very effective initially may need to be adjusted as circumstances change. Some patients find their dose increases during periods when their heart failure is less well controlled and then reduces again once things improve. This is entirely expected and is part of the way furosemide is used in clinical practice.

Monitoring While on Furosemide

Because furosemide affects the kidneys and the balance of electrolytes in the body, regular blood tests are an important part of long term treatment. The main things your doctor will monitor include:

Kidney function. Furosemide can sometimes reduce blood flow to the kidneys, particularly if the body becomes too dry from excessive diuresis. Regular checks ensure the kidneys are tolerating the medication well.

Potassium. Furosemide causes the kidneys to excrete potassium along with salt and water. Low potassium, called hypokalaemia, is one of the more common complications of long term furosemide use and can cause muscle cramps, weakness, and in more serious cases affect heart rhythm. Many patients on furosemide are also prescribed a potassium supplement or a potassium sparing diuretic such as spironolactone for this reason.

Sodium. Less commonly, furosemide can affect sodium levels, which your doctor will also keep an eye on.

What Patients Often Ask

Can I skip a dose if I am going out? This is one of the most common questions. Missing an occasional dose to manage a social commitment is understandable, but doing so regularly or skipping doses frequently can allow fluid to reaccumulate. It is worth having a conversation with your doctor about how to best manage furosemide around your lifestyle.

Will I always need it? This depends entirely on the underlying condition. Some patients take furosemide for a defined period and then stop. Others, particularly those with ongoing heart failure or chronic kidney disease, take it long term as part of their regular medication regimen.

What if I feel very thirsty or dizzy? These can be signs that the body has become too dry, sometimes called volume depletion. If you experience significant thirst, dizziness on standing, or a marked reduction in urine output, contact your doctor rather than simply drinking more fluid, as the dose may need adjustment.

The Importance of a Regular Medication Review

Furosemide does not work in isolation. Most people taking it are also prescribed several other medications for their heart, kidneys, or blood pressure, and many of these can interact with furosemide in ways that affect how the body responds.

A number of commonly prescribed medications can affect electrolyte levels, kidney function, or blood pressure when taken alongside furosemide. These include other blood pressure medications, certain pain relievers, some antibiotics, and a range of other cardiac medications. This is not a reason for concern, but it is a reason for awareness.

A regular medication review with your doctor and pharmacist is genuinely valuable for anyone taking furosemide long term. A pharmacist in particular is well placed to look across your entire medication list and identify any combinations that may warrant closer monitoring or a timing adjustment. This kind of review is not about finding problems, it is about making sure every medication you take is working as well as it possibly can.

It is also worth letting any new doctor, specialist or hospital team know that you are taking furosemide, particularly if you are prescribed a new medication, are unwell with vomiting or diarrhoea, or are preparing for a procedure. These are all situations where a temporary adjustment to your furosemide dose may be appropriate.

Heart Matters Resource

Ask About a Home Medicines Review

If you are taking furosemide alongside three or more other regular medications, you may be eligible for a Home Medicines Review with an accredited pharmacist, fully covered by Medicare. It is one of the most underused resources in Australian primary care and one of the most useful for people on long term cardiac medication.

Read: When in Doubt, Get Checked Out →

Conclusion

Furosemide is one of the most important and widely used medications in cardiovascular and kidney medicine. For many people it makes an enormous difference to daily comfort and quality of life, removing the excess fluid that makes breathing difficult and legs heavy.

If you are taking furosemide, the most important things to stay on top of are your regular blood tests, the timing of your doses, and an open conversation with your doctor or pharmacist whenever something changes. A medication review is not something to put off.

You are not alone in managing this. The team looking after you has prescribed furosemide many times and knows how to adjust it as your needs change. If something does not feel right, ask.

This article provides general information only and is not medical advice. Any decisions about your medication, dose or monitoring should be made in conversation with your cardiologist, GP or pharmacist.

More from Heart Matters

Smartwatches and Heart Health: What They Can and Cannot Detect

smartwatches smartwatch af detection

Key Points

  • Modern smartwatches can detect irregular heart rhythms, record a single-lead ECG, alert you to unusually high or low heart rates, and track heart rate variability. These are genuinely useful features, not marketing gimmicks.
  • Atrial fibrillation detection is the most clinically important capability. AF is often silent and the watch may be the first thing to flag it. This is already changing how cardiologists find and diagnose the condition.
  • A smartwatch ECG is a single-lead recording, equivalent to one view of your heart. A hospital ECG uses twelve leads. The watch cannot detect heart attacks, most structural problems, or many other arrhythmias.
  • An alert from your watch is a prompt to see your doctor, not a diagnosis. A positive AF notification needs to be confirmed with a proper clinical ECG before any treatment is considered.
  • False positives are common, particularly in younger people or those who move around during the recording. A notification does not mean you definitely have a heart problem.

Barely a week passes in a modern cardiology clinic without a patient walking in with their wrist extended, watch face up, ready to show their cardiologist something the device has picked up. Sometimes it is a graph. Sometimes it is a notification. Sometimes it is a recording that looks, unmistakably, like atrial fibrillation.

This is new. And it matters.

Consumer wearables have crossed a threshold in recent years. The technology is no longer novelty. For certain conditions, in certain patients, a smartwatch genuinely picks up things that would otherwise have gone undetected for months or years. For other conditions, it raises alarms that turn out to be nothing. Understanding the difference is what this article is about.

What Can a Smartwatch Actually Measure?

The sensors inside a modern smartwatch are more capable than most people realise. Here is what they are actually doing.

Optical Heart Rate (PPG)

Green LEDs shine into your skin and a sensor measures how light reflects off blood vessels. Changes in blood flow with each heartbeat allow the watch to calculate your heart rate and detect irregularities in the rhythm.

Single-Lead ECG

When you place your finger on the watch crown or back panel, an electrical circuit is completed through your body. The watch records the electrical activity of your heart for 30 seconds, producing a trace similar to Lead I of a standard ECG.

Heart Rate Alerts

Most watches can alert you when your resting heart rate goes above or below thresholds you set. An unexpected heart rate above 120 or below 40 at rest is worth knowing about and worth mentioning to your doctor.

Heart Rate Variability (HRV)

HRV measures the variation in time between heartbeats. It is a marker of recovery, stress, and autonomic nervous system function. Useful for general wellbeing tracking, though not a direct measure of heart disease.

The AF Detection Story

Atrial fibrillation is the most common sustained heart rhythm disorder. It affects millions of people worldwide, its prevalence rises sharply with age, and it significantly increases the risk of stroke. It is also, critically, often completely silent.

Many people live with paroxysmal AF, meaning AF that comes and goes, for months or years before it is ever detected. The Stroke Foundation estimates that AF is responsible for around one in five strokes in Australia. It is only found when a routine ECG happens to catch it, or when a stroke occurs, or when someone puts on a smartwatch.

That last possibility is what has changed the clinical landscape.

400,000+
participants enrolled in the Apple Heart Study, one of the largest cardiac screening studies ever conducted using consumer wearables to detect irregular pulse patterns suggesting atrial fibrillation
Perez MV et al. New England Journal of Medicine, 2019

The Apple Heart Study enrolled more than 400,000 participants and monitored them for irregular pulse patterns. Those who received a notification were sent a wearable ECG patch to confirm the finding. Of those who received notifications and wore the patch, 34 per cent had confirmed AF.

That sounds low. But consider the other side: these were people with no idea they might have AF, no symptoms, who would never have been referred for investigation without the watch. For those in whom AF was confirmed, the watch may genuinely have caught something that would otherwise have caused a stroke first.

The Fitbit Heart Study, published in 2021, found similar results. Using the optical sensor in Fitbit devices, the algorithm identified irregular rhythms in a large population, and those flagged were significantly more likely to have confirmed AF on subsequent testing.

I now see patients regularly who come in because their watch told them something was wrong with their heart rhythm. In several cases, it has been completely right. That is a genuinely new development in how we find atrial fibrillation.

The ECG on Your Wrist: What It Can and Cannot Do

The ECG feature on modern smartwatches is impressive technology. It is also frequently misunderstood.

A hospital 12-lead ECG records the electrical activity of your heart from twelve different angles simultaneously. It allows a cardiologist to assess rhythm, conduction, signs of previous heart attacks, and much more. A smartwatch ECG records from a single perspective for 30 seconds. Here is what that means in practice.

The smartwatch ECG CAN detect The smartwatch ECG CANNOT detect
Atrial fibrillation (irregular rhythm with absent P waves) Heart attacks, including STEMI (requires multiple leads)
Normal sinus rhythm (reassuring during symptoms) Most ischaemia or reduced blood flow to the heart
Some supraventricular arrhythmias if recorded during an episode Most structural heart abnormalities
Obvious bradycardia (very slow heart rate) Bundle branch blocks and conduction disorders reliably
Evidence prompting further investigation A normal result does not rule out heart disease

The most important line in that table is the last one. A normal ECG on your watch, recorded when you feel fine, does not mean your heart is healthy. It means your rhythm was normal at that moment, from that angle.

The Devices: What Each One Offers

Not all smartwatches are equal when it comes to cardiac monitoring. Here is where the main consumer devices currently stand.

Apple Watch

Series 4 and later

AF detection and single-lead ECG

Continuous background AF detection, on-demand 30-second ECG, and high and low heart rate alerts. Regulatory clearance in many countries including Australia. ECG results can be exported as PDF to share with your cardiologist.

Kardia by AliveCor

KardiaMobile and 6L

Dedicated ECG device

A purpose-built personal ECG device rather than a general smartwatch. Clips to a phone or watch band. The 6L version records six leads simultaneously. Worth discussing with your cardiologist if ongoing rhythm monitoring is a priority.

Samsung Galaxy

Series 4 and later

AF detection and single-lead ECG

Single-lead ECG and passive AF detection via the optical sensor. Regulatory clearance varies by country. A capable option for Android users who want cardiac rhythm monitoring in a general-purpose smartwatch.

Fitbit

Sense and Charge 6

Passive AF detection and ECG

Passive AF detection via the optical sensor and on-demand ECG recording. The Fitbit Heart Study provided good evidence for the AF detection capability. A lighter, more fitness-focused option for those who want cardiac monitoring without a full smartwatch.

When Your Watch Sends You an Alert: What to Do

This is where patients most often need guidance. An alert from your watch can feel alarming. Here is how to think about it.

You Have Received an Irregular Rhythm or AF Notification

Do not panic. A single notification, particularly in a younger person or one who was moving during the recording, has a meaningful false positive rate. It is a prompt to investigate, not a confirmed diagnosis.

Do not ignore it either. If your watch flags an irregular rhythm, particularly more than once, or if you also feel palpitations, breathlessness, or dizziness alongside it, contact your GP or cardiologist.

Save the recording. Export the ECG trace from your watch before your appointment if possible. Cardiologists can often see something useful in the raw trace even if the watch algorithm was uncertain.

A clinical ECG is needed for confirmation. No treatment for AF should begin based on a watch notification alone. A proper ECG, and in many cases a Holter monitor, is required to confirm the diagnosis and guide management.

The Limitations You Need to Understand

False positives are real. The optical sensor is susceptible to movement, a loose watch band, and poor skin contact. In younger, lower-risk populations, the majority of AF notifications may be false positives. Unnecessary anxiety and unnecessary investigations are real consequences.

False negatives also occur. Paroxysmal AF that comes and goes may simply not be happening at the moment you record. A normal reading does not mean AF is absent. Your cardiologist may still recommend a longer-duration cardiac monitor even after a normal watch ECG.

It cannot detect a heart attack. Chest pain or pressure that could represent a heart attack is a medical emergency. Call Triple Zero immediately. Do not try to record an ECG on your watch first.

It is not a substitute for clinical care. A smartwatch is a useful supplement to medical monitoring, not a replacement for it.

If You Think You Are Having a Heart Attack

Chest pain, pressure, tightness, pain spreading to the arm or jaw, sweating, or sudden severe breathlessness are potential symptoms of a heart attack. This is a medical emergency.

Call Triple Zero (000) in Australia immediately. Do not drive yourself to hospital. Do not attempt to record an ECG on your watch first. Time matters enormously and delays cost lives.

What Your Cardiologist Wants You to Know

Wear it consistently. Passive background monitoring is more valuable than on-demand recordings. Wearing it overnight, when resting heart rate is naturally lower, adds real diagnostic value.

Bring your data to appointments. Many watches allow you to export your heart rate history and ECG recordings. Having this at a consultation is genuinely useful.

Do not over-interpret every reading. A slight irregularity on one recording, a brief period of elevated heart rate during exercise, a single unusual-looking trace: these should be noted but not catastrophised. Context is provided by the clinical picture, not the watch alone.

Ask your cardiologist about dedicated ECG devices. If you have already been diagnosed with AF or another arrhythmia and your cardiologist wants you to monitor for episodes, a purpose-built ECG device may produce better-quality recordings. Your cardiologist can advise which approach suits your situation.

Conclusion

Can smartwatches detect heart problems? Yes, some of them, in some circumstances, with meaningful accuracy. The AF detection story in particular is genuinely compelling, and cardiologists are seeing its real-world impact every week.

But a smartwatch is not a cardiologist on your wrist. It is a screening tool with real limitations, a false positive rate that deserves respect, and a fundamental inability to diagnose the most time-critical cardiac emergencies.

Used well, with realistic expectations and a good relationship with a doctor who can contextualise what it finds, a modern smartwatch is a valuable addition to your heart health toolkit.

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Heart Health During Pregnancy: What You Need to Know

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Key Points

  • Pregnancy places extra demands on the heart, blood volume rises by up to 50%, the heart beats faster, and the body works harder. These changes are normal and expected.
  • Many symptoms in pregnancy, palpitations, breathlessness, fatigue, and mild ankle swelling, are a normal part of these adaptations, not a sign that something is wrong.
  • Some conditions, including high blood pressure, heart rhythm changes, and rarely peripartum cardiomyopathy or SCAD, can occur during or after pregnancy and are important to be aware of.
  • Most of these conditions are manageable when recognised early, and your maternity and cardiology teams are experienced in supporting women through them.
  • If you have a pre-existing heart condition, planning your pregnancy with your specialist team makes a significant difference to outcomes.
  • Complications in pregnancy can also be a window into your future heart health, making follow-up after delivery an important part of long-term wellbeing.

Pregnancy is one of the most remarkable things the human body does. To support a growing baby, your heart and circulation adapt in ways that are genuinely extraordinary, and for the vast majority of women, pregnancy is a safe and healthy experience.

That said, the heart is working harder than usual, and it helps to understand what is normal, what is worth mentioning, and, in the rare cases where something does need attention, what good care looks like. This article is designed to give you that picture clearly and honestly, without causing unnecessary alarm.

What happens to your heart during pregnancy?

From the earliest weeks of pregnancy, your cardiovascular system begins to adapt. Blood volume increases by up to 50% to support the placenta and baby. Your heart beats faster, typically 10 to 20 beats per minute more than usual. And the total output of blood your heart pumps each minute increases significantly, often by 30 to 50%.

Blood pressure tends to fall slightly in the first and second trimester as blood vessels relax and widen, before gradually returning toward your normal level in the third trimester. These are not signs of anything going wrong, they are the body doing exactly what it is supposed to do.

What this means practically is that your heart is doing more work. And like any system under increased load, it can produce symptoms that, understandably, feel concerning, even when they are entirely expected.

Symptoms that are usually a normal part of pregnancy

Many of the cardiovascular symptoms women notice during pregnancy are simply the body adjusting to its new demands. They are worth knowing about so they do not come as a surprise.

Symptom Why it happens
Palpitations The faster heart rate and increased blood volume can make you more aware of your heartbeat, particularly at rest or at night
Breathlessness The diaphragm is pushed upward by the growing uterus, and the body’s oxygen demands increase, mild breathlessness on exertion is very common
Fatigue The cardiovascular system is working significantly harder, tiredness, especially in the first and third trimester, is expected
Ankle swelling Fluid retention is common, particularly later in pregnancy, due to hormonal changes and pressure on the pelvic veins
Light-headedness Blood pressure naturally falls in early pregnancy, standing up quickly can occasionally cause a brief dizzy sensation

In my experience, the women who feel most at ease during pregnancy are those who know what to expect from their body, and who feel confident enough to speak up when something doesn’t feel right.

These symptoms are common and usually reassuring when they occur in isolation and do not dramatically worsen. If any of them feel sudden, severe, or out of proportion, they are always worth mentioning to your midwife or doctor, not because they are likely to be serious, but because it is always better to be certain.

Blood pressure in pregnancy

Blood pressure monitoring is one of the most important aspects of antenatal care, and for good reason. While mild falls in blood pressure early in pregnancy are normal, a significant rise, particularly in the second half of pregnancy, needs attention.

Gestational hypertension

Some women develop high blood pressure after 20 weeks of pregnancy without any other features. This is called gestational hypertension. It often resolves after delivery, but it does require monitoring and sometimes medication to keep blood pressure within a safe range for both mother and baby.

Pre-eclampsia

Pre-eclampsia is a more significant condition that combines high blood pressure with signs that other organs, typically the kidneys or liver, are under stress. It affects around 2–8% of pregnancies. Symptoms can include persistent headache, visual changes, upper abdominal pain, and sudden worsening of swelling.

Pre-eclampsia is taken seriously because of its potential to progress, but it is also one of the most closely monitored conditions in obstetric care. Women who develop it are supported carefully, and the condition resolves after delivery. If you have risk factors such as a first pregnancy, multiple pregnancy, obesity, diabetes, or a family history of pre-eclampsia, your team will be watching closely from the outset.

2–8%
of pregnancies are affected by pre-eclampsia, a closely monitored and manageable condition that resolves after delivery

Heart rhythm changes in pregnancy

Palpitations are among the most common cardiac symptoms reported during pregnancy, and in the vast majority of cases they are entirely benign. The combination of a faster heart rate, higher blood volume, and the hormonal environment of pregnancy can make extra heartbeats, known as ectopic beats, more noticeable than usual.

Most of the time, these are harmless. They do not require treatment and typically settle after delivery. However, if palpitations are frequent, prolonged, associated with dizziness or fainting, or feel like a sustained rapid or irregular rhythm, they are worth reporting. An ECG is quick, painless, and safe in pregnancy, and can provide important reassurance or identify whether any further assessment is needed.

Some women with pre-existing heart rhythm conditions, such as supraventricular tachycardia (SVT), find that episodes become more frequent during pregnancy. This is manageable with appropriate monitoring and, where needed, treatment that is safe for the baby.

Peripartum cardiomyopathy

Peripartum cardiomyopathy is a rare condition in which the heart muscle becomes weakened in the final month of pregnancy or in the months following delivery. It is uncommon, affecting approximately 1 in 1,000 to 1 in 4,000 pregnancies, but it is important to be aware of.

The symptoms can overlap with normal pregnancy experiences, breathlessness, fatigue, and swelling, which is why any significant or rapidly worsening symptoms in late pregnancy or after delivery deserve prompt attention. When recognised early, the outlook is genuinely encouraging. Most women with peripartum cardiomyopathy recover well with appropriate treatment, and many regain normal heart function within months.

Risk factors include older maternal age, multiple pregnancy, pre-eclampsia, and African heritage. If you develop new and significant breathlessness, difficulty lying flat, or swelling that seems out of proportion in the weeks around delivery, mention it to your doctor promptly, not because it is likely to be serious, but because early assessment makes a real difference.

SCAD, Spontaneous Coronary Artery Dissection

Spontaneous coronary artery dissection, or SCAD, is a rare but important cause of heart attack in young women, and it has a particular association with pregnancy and the postpartum period. It occurs when a small tear develops in the wall of a coronary artery, disrupting blood flow to part of the heart muscle.

SCAD can feel like a classic heart attack, chest pain, breathlessness, and sometimes pain radiating to the arm or jaw. In the context of a recently pregnant or postpartum woman, these symptoms should always be taken seriously and assessed urgently. The good news is that the majority of women with SCAD recover well, and with the right specialist support, outcomes are positive.

We have a dedicated article on SCAD on this site if you would like to understand more about this condition.

Pre-existing heart conditions and pregnancy

Women with known heart conditions, including congenital heart disease, valve disease, or cardiomyopathy, can and do have successful pregnancies. The key is planning ahead with a specialist team who can assess how pregnancy is likely to affect your individual situation and put appropriate monitoring in place from early on.

This kind of joint care, between your cardiologist and your obstetrician, makes an enormous difference. It allows potential issues to be anticipated rather than reacted to, and ensures that any medications you are on are reviewed for safety in pregnancy well in advance.

If you have a heart condition and are thinking about starting a family, a preconception appointment with your cardiologist is one of the most valuable investments you can make.

Investigations that are safe in pregnancy

If your doctor or midwife wants to investigate a cardiac symptom during pregnancy, there are several tests that are completely safe and commonly used.

An ECG is painless and safe at any stage of pregnancy. An echocardiogram uses ultrasound, the same technology used to image your baby, and carries no radiation risk whatsoever. Blood tests, including markers of heart stress, can also be checked safely if there is clinical concern. Your team will only request investigations when they are genuinely needed, and they are experienced in interpreting results in the context of pregnancy’s normal physiological changes.

Medications in pregnancy

Some cardiac medications are safe to continue during pregnancy, others need to be adjusted, and a small number should be avoided. This is an area where the guidance is specific to each person and each condition, a medication that is appropriate for one woman may not be right for another.

If you are on cardiac medication and become pregnant, or are planning a pregnancy, speak with your cardiologist as early as possible. Do not stop any medication without guidance, as this can sometimes carry its own risks. The goal is always to find the approach that best protects both you and your baby.

After pregnancy, looking after your heart long-term

The period after delivery is an important one for heart health monitoring. Peripartum cardiomyopathy, SCAD, and postpartum pre-eclampsia can all emerge or continue in the weeks after birth, so paying attention to new symptoms after delivery matters just as much as during pregnancy.

Beyond the immediate postpartum period, there is growing evidence that complications in pregnancy, particularly pre-eclampsia, gestational diabetes, and preterm delivery, are associated with a modestly increased risk of cardiovascular disease later in life. This does not mean that heart disease is inevitable; it means that your pregnancy history is a useful part of your overall health picture.

When you see your GP or cardiologist in future years, mention any significant pregnancy complications. It allows your longer-term cardiovascular risk to be assessed appropriately and helps ensure that any preventive measures, lifestyle, blood pressure monitoring, cholesterol checks, are put in place at the right time.

♀
Heart Matters · Hub Page

Women’s Heart Health

Heart disease affects women differently, from symptoms to risk factors to treatment responses. Our dedicated hub covers everything women need to know, written by cardiologists and nurses who specialise in women’s cardiovascular health.

Explore the Hub →

Questions to Ask Your Midwife or Cardiologist

Going into appointments prepared helps you get the most from the time you have. Here are some questions worth raising:

Questions worth asking

  • The palpitations I am experiencing, are these something you would expect at this stage of pregnancy, or do they warrant further investigation?
  • My blood pressure has been a little high, what level would prompt you to consider medication, and what are the safest options in pregnancy?
  • I had pre-eclampsia in a previous pregnancy, does this change how you will monitor me this time?
  • I have a pre-existing heart condition, who should I be seeing through this pregnancy, and how often?
  • After delivery, what follow-up should I have for my heart health, and over what timeframe?

Conclusion

Pregnancy is a time of extraordinary change for the heart and circulation, and for the vast majority of women, those changes unfold safely, supported by a body that is remarkably well designed for the task. Most cardiac symptoms during pregnancy are a normal part of that adaptation, not a warning sign.

Where conditions do arise, whether blood pressure changes, rhythm disturbances, or the rarer but important conditions like peripartum cardiomyopathy or SCAD, the outcomes with good care are genuinely encouraging. Awareness is not the same as anxiety; knowing what to look for means that if something does need attention, it gets it promptly.

Your maternity and cardiac teams are there to support you at every stage. Trust your instincts, speak up when something feels different, and know that asking questions is always the right thing to do.

Free Resources

Our Heart Glossary explains terms like pre-eclampsia, cardiomyopathy, arrhythmia, and echocardiogram in plain language, helpful to have alongside your antenatal appointments.

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