Procedure
Right heart catheterization with exercise
Measuring the pressures inside the heart and lungs directly — and then measuring them again while you exercise, because for many patients that is the only time anything is abnormal.
The Point of It
Why the exercise part matters
A patient who is breathless climbing stairs is describing a problem that exists under load. Measuring them lying still measures the one situation in which they feel well.
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Symptoms happen during exertion, not at rest
A patient whose breathlessness appears when they climb stairs is describing a problem that exists when the heart is working hard. Measuring them lying still measures the one condition under which they feel fine.
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Resting numbers can be entirely normal
In some patients abnormal haemodynamics are obvious at rest. In others they are only provoked by exercise — the pressures are normal on the table until the legs start working, and then they are not. A resting-only study reports those patients as normal and the search for a diagnosis stops.
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The thresholds are defined
A wedge pressure of 15 mmHg or above at rest, or rising to 25 mmHg or above during supine exercise, supports a left-sided cause — heart failure with preserved ejection fraction, in many cases. Around 20 mmHg is the corresponding figure for upright exercise. Those cut-offs are what turn a symptom into a diagnosis.
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It changes what happens next
The distinction is not academic. Pulmonary vascular disease and heart failure with preserved ejection fraction are managed differently, and treating one as though it were the other does not help the patient. An exercise study is often what settles which conversation to have.
The Measurements
What the study records
Pressure, flow, and the relationship between them. An echocardiogram estimates these; a catheter measures them.
- Pressures, chamber by chamber
- A catheter passed through a vein records pressure in the right atrium, then the right ventricle, then the pulmonary artery. A small balloon at its tip can be floated into a branch of the pulmonary artery and inflated, which briefly stops flow in that branch and lets the catheter read the pressure being transmitted back from the left side of the heart — the pulmonary capillary wedge pressure.
- Flow, not just pressure
- The study also measures how much blood the heart is actually moving each minute. Pressure alone can mislead: a high pressure with a low output means something quite different from a high pressure with a normal one, and the treatment that follows is different too.
- Where the problem sits
- Together those numbers separate a problem in the lung circulation from a problem with the left side of the heart — pre-capillary from post-capillary, in the language of the field. It is the distinction that decides whether a patient is treated for pulmonary vascular disease or for heart failure, and it cannot be made reliably from an echocardiogram.
Indications
Why a study gets ordered
Usually because the non-invasive tests have not explained the symptoms, and the symptoms are real.
Breathlessness on exertion without an explanation
Where an echocardiogram, lung function testing, and a stress test have not accounted for the symptoms, direct measurement often does.
Suspected pulmonary hypertension
Catheterisation remains the reference standard for diagnosing pulmonary hypertension and for classifying which kind it is. An echocardiogram can raise the suspicion; it cannot confirm it.
Suspected heart failure with preserved ejection fraction
HFpEF is difficult to diagnose precisely because the pumping function looks normal. Exercise haemodynamics can demonstrate it directly rather than by inference.
Before and after rhythm procedures
Filling pressures are part of understanding why atrial fibrillation is happening and how much of a patient's symptom burden the rhythm actually accounts for.
Filling pressures and atrial fibrillation are connected, which is why this study sits alongside the rhythm work rather than apart from it. Understanding the haemodynamics can change how much of a patient’s breathlessness is attributed to the rhythm and how much to the pressures behind it — see atrial fibrillation ablation.
The Visit
What the day looks like
Sedation is kept deliberately light. You need to be able to exercise, and deep sedation would change the very numbers being measured.
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Before you come in
You will be given fasting instructions and told which medications to take. Diuretics in particular may be adjusted, because taking a large dose that morning alters the very pressures the study is trying to measure. Arrange for someone to drive you home.
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Access, and light sedation
A vein is accessed at the neck, arm, or groin under local anaesthetic. Sedation is kept deliberately light — deep sedation changes breathing and haemodynamics, and you need to be able to exercise later in the study.
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Resting measurements
The catheter is advanced through the right heart, recording pressures at each step, and the wedge pressure and cardiac output are measured with you lying quietly. These are the baseline numbers everything else is compared against.
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The exercise
You then exercise with the catheter still in place, pedalling against increasing resistance on a Lode cycle ergometer mounted at the table, while the pressures are recorded continuously. A calibrated ergometer matters more than it sounds: the workload is set in watts and stepped up in defined increments, so the pressures can be reported against a known load rather than against an impression of how hard you were working. You will be asked to keep going until you reach the symptom that brought you here — which is the point, uncomfortable as it is.
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Recovery and going home
The catheter is removed, the access site is held until it seals, and you rest for a defined observation period. Most patients go home the same day. The full set of measurements is interpreted together rather than read off one at a time, so results are usually discussed at follow-up.
Risks
What can go wrong, and how likely it is
This is among the better-tolerated invasive studies, and it is still an invasive study.
Problems at the access site
Bruising and tenderness are common. Less often the vein is damaged, a collection of blood forms, or — where the neck is used — the lung is nicked, which can require a drain.
Arrhythmia while the catheter is in the heart
A catheter passing through the right ventricle commonly provokes a few extra beats, and occasionally a short run of a faster rhythm. It usually settles as the catheter is repositioned; monitoring is continuous throughout.
Injury from the balloon
The wedge measurement requires inflating a balloon in a small branch of the pulmonary artery. Leaving it inflated longer than necessary risks injuring the vessel, which is why the measurement is taken briefly and released.
Infection
Any catheter crossing the skin carries a risk of infection, kept low by sterile technique.
The exercise itself
Exercising to the point of symptoms is the purpose of the study and is done under continuous monitoring, with the team present and the test stopped if anything concerning appears. Being pushed to breathlessness is expected; being pushed past what is safe is not.
Sources
Questions about your procedure?
Our team will confirm your date, walk you through preparation, and answer questions about insurance, sedation, and recovery.