Prof. Peter Barlis

Professor Peter Barlis (MBBS, MPH, PhD, FESC, FACC, FSCAI, FRACP) is an Interventional Cardiologist and the founding editor of Heart Matters. With expertise in coronary artery disease, advanced cardiac imaging, and interventional cardiology — and fellowships of the European Society of Cardiology, the American College of Cardiology, and the Royal Australasian College of Physicians — he brings the highest level of clinical authority to everything published on this site. Heart Matters was founded on Professor Barlis's belief that patients who understand their condition are less frightened and better equipped to make decisions about their care. Every article on this site reflects that commitment.

A High Calcium Score: What Does It Really Mean?

May 6, 2026March 14, 2025

A high calcium score can feel like devastating news, but a number without context is rarely good medicine. Here is what your result actually means and what happens next.

HFrEF and HFpEF: Understanding the Two Types of Heart Failure

April 25, 2026February 25, 2025

Key Points

Heart failure does not mean the heart has stopped, it means the heart is not pumping as efficiently as it should, and cannot fully keep up with the body’s demands.
Doctors describe heart failure in two main ways, based on whether the heart’s pumping strength is reduced or whether it is normal but the heart has become stiff. Both cause similar symptoms.
The term “ejection fraction” refers to the percentage of blood the heart pumps out with each beat. A normal ejection fraction is above 55%. In heart failure with reduced ejection fraction it is below 40%.
HFrEF, heart failure with reduced ejection fraction, means the heart muscle is pumping less powerfully than normal. HFpEF, heart failure with preserved ejection fraction, means the pumping strength appears normal but the heart has become stiff and does not fill properly between beats.
Both types are treatable. The specific medications and management approach differ between the two, which is why knowing which type you have matters for your treatment plan.

Being told you have heart failure is frightening enough. Being told you have “HFrEF” or “HFpEF”, or that your ejection fraction is reduced or preserved, adds a layer of medical terminology that can leave patients more confused than informed.

These terms are important, they describe which type of heart failure you have and directly influence which treatments are most appropriate for you. But they are not complicated once they are explained in plain language. This article does exactly that.

What Is Ejection Fraction?

The heart is a pump. With every beat, it squeezes blood out of its main pumping chamber, the left ventricle, and sends it out to the rest of the body. The ejection fraction is simply the percentage of blood in that chamber that gets pumped out with each beat.

It is measured using an echocardiogram, an ultrasound of the heart that shows how the heart muscle is moving and how much blood is being pumped with each beat. It is one of the most important single measurements in cardiology.

In a healthy heart, the left ventricle pumps out roughly 55 to 70% of the blood it contains with each squeeze. This is a normal ejection fraction. The remaining blood stays in the ventricle and is topped up again as the heart relaxes and refills before the next beat.

When the heart muscle is weakened, as happens in certain types of heart failure, it squeezes less powerfully, and a smaller percentage of blood is pumped out with each beat. This is what a reduced ejection fraction means.

The Two Main Types of Heart Failure

HFrEF, Heart Failure with Reduced Ejection Fraction

In HFrEF, pronounced “HF-ref”, the heart muscle has weakened and is not squeezing as powerfully as it should. The ejection fraction is below 40%, meaning less than 40% of the blood in the left ventricle is being pumped out with each beat. The heart is working hard but not achieving enough forward output.

The symptoms this produces, breathlessness, fatigue, ankle swelling, reduced exercise tolerance, reflect the fact that the body’s tissues are not receiving as much blood and oxygen as they need. The heart compensates as best it can, but over time the gap between what the body demands and what the heart can deliver produces the characteristic symptoms of heart failure.

HFrEF has an excellent range of treatments available, in fact the evidence base for treating HFrEF is one of the strongest in all of cardiology. A combination of four medication classes, known as quadruple therapy, including SGLT2 inhibitors, beta-blockers, ACE inhibitors, and mineralocorticoid receptor antagonists has been shown to significantly improve both symptoms and long-term outcomes. We cover this in detail in our dedicated heart failure treatment article.

HFpEF, Heart Failure with Preserved Ejection Fraction

In HFpEF, pronounced “HF-pef”, the heart’s pumping strength appears normal on an echocardiogram. The ejection fraction is above 50%, meaning the heart is squeezing well. But the patient still has heart failure symptoms, breathlessness, fatigue, reduced exercise capacity, because something else is going wrong.

The problem in HFpEF is stiffness. The heart muscle has become less flexible, it does not relax and fill between beats as easily as it should. Think of squeezing a stiff rubber ball compared to a soft one, the stiff ball takes more effort to compress and springs back less readily. When the heart muscle is stiff, it fills less efficiently between beats, pressures rise within the heart, and those elevated pressures back up into the lungs, producing breathlessness and the other symptoms of heart failure despite normal pumping strength.

HFpEF is more common in older patients, women, people with high blood pressure, obesity, and diabetes. Managing the underlying conditions that contribute to cardiac stiffness, blood pressure control, weight management, blood sugar control, is a central part of HFpEF treatment alongside specific medications.

55%+

A normal ejection fraction is above 55%, meaning the heart pumps out more than half the blood in its main chamber with every beat. Below 40% is considered reduced. Between 40% and 55% is sometimes called mildly reduced or borderline.

Why Does the Distinction Matter?

The two types of heart failure produce very similar symptoms, which is why an echocardiogram is needed to distinguish them rather than clinical assessment alone. But the treatment approaches differ in important ways.

The medications that have the strongest evidence in HFrEF, particularly certain beta-blockers, ACE inhibitors, and SGLT2 inhibitors, have been studied extensively in that specific population and shown to improve outcomes significantly. HFpEF research has historically lagged behind, but SGLT2 inhibitors have now shown meaningful benefit in HFpEF as well, and the treatment landscape is improving rapidly.

Knowing which type you have means your clinical team can apply the right evidence to your specific situation. Regular follow-up including BNP or NT-proBNP blood tests helps the clinical team monitor how hard the heart is working and whether treatment is achieving the right effect.

When a patient is told they have heart failure, one of the first questions I want answered is which type, because the management pathway differs. An echocardiogram gives us that answer quickly, and it changes the conversation about which treatments are most likely to help.

— Prof. Peter Barlis, Interventional Cardiologist

A Note on Borderline Ejection Fraction

Some patients are told their ejection fraction is “mildly reduced” or “borderline”, typically a reading between 40% and 55%. This sits between the two main categories and is sometimes called HFmrEF, heart failure with mildly reduced ejection fraction. It shares features of both types and is managed on an individualised basis. If you have been given this term and are unsure what it means for your treatment, asking your cardiologist to clarify which treatment approach applies to you is a very reasonable question.

What Both Types Have in Common

Regardless of which type of heart failure you have, the broader management principles are similar, monitoring symptoms, daily weighing to detect fluid accumulation early, appropriate exercise within your limits, salt and fluid awareness, and regular follow-up with your clinical team.

Understanding which type of heart failure you have is the starting point, not the end of the conversation. The most important next step is working with your cardiologist to ensure your treatment is optimised for your specific type, your specific symptoms, and your specific circumstances. We cover all of these management approaches in detail in our heart failure treatment article.

Questions worth asking at your next appointment

Which type of heart failure do I have, HFrEF or HFpEF, and what does that mean for my treatment?
What is my ejection fraction, and has it changed since my last echocardiogram?
Am I on the right medications for my specific type of heart failure?
Are there conditions contributing to my heart failure, blood pressure, diabetes, weight, that we should be managing more aggressively?
What symptoms should prompt me to contact the team between appointments?

Heart Matters Resource

When in Doubt, Get Checked Out

If you have been told you have heart failure and are not sure which type, or if your symptoms have changed, that is a conversation worth having with your cardiologist promptly rather than waiting for the next routine appointment.

Read: When in Doubt, Get Checked Out →

Conclusion

HFrEF and HFpEF are not two different diseases, they are two different mechanisms by which the heart fails to meet the body’s demands. One involves a weakened pump, the other a stiff one. Both produce similar symptoms, both are diagnosed with an echocardiogram, and both are treatable, though the specific treatment approaches differ.

Knowing which type you have puts you in a stronger position to understand your treatment and ask the right questions at your appointments. It is not a label to be feared, it is a piece of information that your clinical team uses to make your management as targeted and effective as possible.

Your heart has two ways of struggling, and medicine has effective answers for both.

The Coronary Calcium Score: What It Measures and What to Expect

April 6, 2026February 16, 2025

The coronary calcium score is one of the most powerful tests in preventive cardiology, and one of the most misunderstood. Here is what the scan involves and what the result means.

Inflammation and Heart Disease: The Hidden Driver Behind Atherosclerosis, Pericarditis, and More

May 6, 2026February 14, 2025

Inflammation quietly drives heart disease over decades, and it is more modifiable than most people realise. Here is what the evidence shows and what you can do about it.

Shortness of Breath and the Heart: When Breathlessness Is a Cardiac Signal

April 25, 2026February 4, 2025

Key Points

Shortness of breath, breathlessness, is one of the most common reasons people see a cardiologist, and one of the most diagnostically important symptoms in cardiovascular medicine.
The heart and lungs work as a unit. When the heart is not pumping efficiently, fluid backs up into the lungs, producing breathlessness that is often the first signal something is wrong.
Breathlessness on exertion that is new, progressive, or out of proportion to effort deserves cardiac assessment, even if it seems to have an obvious non-cardiac explanation.
A normal BNP blood test and a normal echocardiogram together substantially reduce the likelihood of a cardiac cause and redirect the investigation efficiently.
Breathlessness at rest, particularly when lying flat, waking you from sleep, or accompanied by chest discomfort, requires prompt assessment, not a wait-and-see approach.

Breathlessness is such a common human experience, after exercise, after a shock, at altitude, that it is easy to normalise it when it shouldn’t be. Patients often come to me having been breathless for months, having attributed it to being unfit, getting older, putting on weight, or stress.

Sometimes those explanations are correct. But breathlessness is also one of the most important cardiac symptoms there is, and one of the most frequently under-investigated. The heart and lungs are inseparable in their function, and when the heart begins to struggle, the lungs are often the first place it shows.

Understanding what cardiac breathlessness feels like, what causes it, and when to seek assessment is genuinely important, because the earlier a cardiac cause is identified, the better the options for treatment.

Why the Heart Causes Breathlessness

The heart-lung connection

The left side of the heart receives oxygenated blood from the lungs and pumps it out to the body. When the left ventricle is not pumping efficiently, whether from heart failure, a weak muscle, a valve problem, or elevated pressures, blood backs up through the pulmonary circulation. Fluid accumulates in the lung tissue itself, making the lungs stiffer and gas exchange less efficient.

The result is breathlessness, the sensation of not being able to get enough air in, of breathing being harder than it should be. At rest this may be subtle or absent. With exertion, when the heart needs to increase its output and cannot do so adequately, the breathlessness becomes apparent.

Why it so often gets missed

The insidious onset of cardiac breathlessness is part of why it gets missed. It rarely arrives suddenly, it creeps in gradually, week by week. A person who used to walk briskly up a hill now walks slowly. Someone who carried groceries up the stairs now takes two trips. The brain unconsciously recalibrates what feels normal, and by the time the breathlessness is significant enough to seek medical attention, a meaningful period of cardiac stress may have already accumulated.

One of the most telling questions I ask in clinic is: “What could you do six months ago that you can’t do now?” That question unlocks the real story, because patients adapt so well to progressive breathlessness that they often don’t realise how much their functional capacity has changed until someone asks directly.

Cardiac Causes of Breathlessness

Heart failure

Heart failure, reduced pump function of the left ventricle, often expressed as a reduced ejection fraction, is the most common cardiac cause of breathlessness. The failing heart cannot maintain adequate output, pressures rise in the pulmonary circulation, and fluid accumulates in the lungs. Breathlessness on exertion is the hallmark symptom, often accompanied by fatigue, ankle swelling, and reduced exercise tolerance.

Heart failure with preserved ejection fraction (HFpEF), where the pumping function appears normal but the heart muscle is stiff and fills abnormally, is increasingly recognised and produces breathlessness through a subtly different mechanism, but the symptom pattern is similar.

Valve disease

Significant valve disease, particularly aortic stenosis and mitral regurgitation, can produce breathlessness as the heart compensates for abnormal flow across the valve. Aortic stenosis in particular can progress for years without symptoms, then produce breathlessness, chest pain, or fainting as the valve area becomes critically narrow. An echocardiogram identifies valve problems with precision.

Atrial fibrillation

AF causes breathlessness in two ways. The irregular rhythm and often elevated heart rate reduce the efficiency of cardiac filling and output, particularly in people whose hearts rely on the atrial contraction component that AF abolishes. Additionally, AF is often a manifestation of underlying cardiac disease that itself causes breathlessness. Many people first notice their AF through unexplained breathlessness rather than palpitations.

Coronary artery disease

Significant narrowings in the coronary arteries can cause breathlessness as an anginal equivalent, particularly in women, in people with diabetes, and in older adults, where classic chest pain may be absent or minimal. Breathlessness on exertion that resolves with rest, in someone with cardiovascular risk factors, should always raise the possibility of ischaemia.

Pulmonary hypertension

Elevated pressure in the pulmonary circulation, whether from left heart disease, lung disease, or primary pulmonary arterial hypertension, causes breathlessness that can be severe and progressive. It is a diagnosis that requires specialist assessment but is important not to miss, particularly in younger patients with breathlessness that seems disproportionate to their apparent health.

Non-Cardiac Causes, Important to Distinguish

Not all breathlessness is cardiac, and part of the clinical task is efficiently distinguishing between causes. The most common non-cardiac causes include asthma and COPD, pulmonary embolism (blood clot in the lungs), anaemia, obesity, deconditioning, anxiety and panic disorders, and thyroid disease.

Several of these can coexist with cardiac disease, which is why the investigation is rarely a matter of ruling out one thing, it is a matter of understanding which factor is the dominant contributor.

Heart failure

Fluid backs up into the lungs as the heart struggles to maintain output. Progressive exertional breathlessness is the hallmark.

Valve disease

Aortic stenosis and mitral regurgitation both produce breathlessness as the heart compensates for abnormal valve function.

Atrial fibrillation

AF reduces cardiac efficiency and output. Many people first notice AF through breathlessness rather than palpitations.

Coronary artery disease

Breathlessness on exertion as an anginal equivalent, particularly in women, older adults, and people with diabetes where chest pain may be absent.

Pulmonary hypertension

Elevated pressure in the pulmonary circulation, causes breathlessness that can be progressive and severe. Important not to miss in younger patients.

Non-cardiac causes

Asthma, COPD, pulmonary embolism, anaemia, deconditioning, anxiety, and thyroid disease, all require consideration and may coexist with cardiac causes.

Warning Patterns, When to Act Promptly

Not all breathlessness requires the same urgency. But certain patterns warrant prompt assessment rather than a routine appointment.

Pattern	What it may suggest	Action
Breathlessness at rest or with minimal activity	Decompensated heart failure, pulmonary embolism, acute cardiac event	Same-day medical assessment
Waking at night breathless, needing to sit up	Paroxysmal nocturnal dyspnoea, a hallmark of heart failure	Prompt cardiac assessment
Breathlessness lying flat, needing extra pillows	Orthopnoea, fluid redistribution in heart failure	Prompt cardiac assessment
Sudden severe breathlessness with chest pain	Acute pulmonary oedema, pulmonary embolism, aortic dissection	Emergency services immediately
Progressive exertional breathlessness over weeks to months	Heart failure, valve disease, coronary disease, anaemia	Medical review within days
Breathlessness with palpitations	AF or other arrhythmia reducing cardiac output	ECG and medical review

Sudden severe breathlessness at rest particularly with chest pain, pale or clammy skin, or a feeling of impending doom, is a medical emergency. Call emergency services immediately. Australia: 000, UK: 999, USA/Canada: 911, Europe: 112.

How Breathlessness Is Investigated

The first steps

The initial assessment of breathlessness combines a clinical history, what brings it on, how long it has been present, whether it wakes you at night, what makes it better or worse, with a physical examination and targeted investigations.

A 12-lead ECG provides immediate information about heart rhythm, rate, and any electrical evidence of heart disease. Blood tests, including BNP or NT-proBNP, full blood count for anaemia, thyroid function, and kidney function, provide important baseline information. A chest X-ray can show pulmonary congestion, cardiomegaly, or lung pathology.

The echocardiogram, the key cardiac test

An echocardiogram is the most informative single cardiac investigation for breathlessness. It assesses left ventricular function and ejection fraction, valve structure and function, chamber dimensions, and filling pressures. A normal echocardiogram makes a primary cardiac cause of breathlessness significantly less likely and redirects investigation efficiently.

BNP and NT-proBNP, the cardiac stress markers

Elevated BNP or NT-proBNP in someone with breathlessness strongly supports a cardiac cause and typically leads directly to echocardiography. A normal level in someone with breathlessness is genuinely reassuring, it makes significant heart failure unlikely. We have a dedicated article on BNP in the Diagnostic Tests section.

Further investigation

Depending on the findings, further investigation may include a CT coronary angiogram or stress test to assess for coronary disease, pulmonary function tests to assess for lung disease, CT pulmonary angiography for pulmonary embolism, or right heart catheterisation for pulmonary hypertension assessment.

Treatment Depends on the Cause

Breathlessness is a symptom, not a diagnosis, and its treatment follows directly from identifying and treating the underlying cause. Heart failure responds to the quadruple therapy regimen. Valve disease may require intervention when it reaches the threshold for repair or replacement. AF is treated with rate control, rhythm control, and anticoagulation. Coronary disease is managed with medication, stenting, or surgery depending on the anatomy and severity.

The most important step in every case is getting to the correct diagnosis, because treating breathlessness symptomatically without understanding its cause is never the right approach in cardiology.

Questions worth asking at your next appointment

Is my breathlessness likely to be cardiac, and what investigations will confirm or exclude this?
Should I have a BNP blood test and an echocardiogram as a starting point?
How do I distinguish cardiac breathlessness from breathlessness due to lung disease, anaemia, or deconditioning?
My breathlessness is worse lying flat / waking me at night, does that change the urgency?
What functional changes should I watch for that would suggest my breathlessness is worsening?

Free Download, Heart Matters

Our Heart Health Risk Factor Checklist covers 12 cardiovascular risk categories, a useful tool to complete before any appointment investigating breathlessness, to ensure no relevant risk factors are overlooked.

Download the Risk Factor Checklist →

Heart Matters Resource