What to Expect During Right Heart Catheterization for PH?

A right heart catheterization (RHC) is a procedure where a thin tube is guided to your heart to measure blood pressures directly ^[1]. While an echocardiogram is a useful non-invasive screening tool, it only estimates pressures ^[2]. An RHC is the medical standard recommended to get the direct measurements needed to confirm pulmonary arterial hypertension (PAH) and guide specialized treatments safely ^{[3] [4]}.

Why Can’t I Just Have an Echocardiogram?

An echocardiogram (or “echo”) uses sound waves to look at your heart’s structure and estimate pressures. It is excellent for estimating the probability of pulmonary hypertension and assessing right-heart strain, but its pressure estimates can have a wide margin of error ^{[2] [5]}.

More importantly, an echocardiogram cannot reliably measure your pulmonary arterial wedge pressure (PAWP) or calculate your pulmonary vascular resistance (PVR) ^[6]. These direct measurements are critical to distinguish precapillary pulmonary hypertension (which includes PAH) from pulmonary hypertension caused by left-sided heart disease ^[7].

Using PAH-specific medications for left-heart-related pulmonary hypertension can be ineffective or harmful. Because of this, medical guidelines (such as those from the European Society of Cardiology and European Respiratory Society) recommend an RHC to confirm the hemodynamic diagnosis before PAH-specific drugs are prescribed ^{[3] [8]}.

Is the Procedure Painful? What Will I Feel?

Having a catheter placed in your heart can sound frightening. Most people do not feel the catheter moving through their veins, but sensations vary, and you should always tell the medical team if you are uncomfortable. It is normal to feel anxious, so communicate your fears to your doctors beforehand.

Here is what you can expect during the procedure:

• Local Anesthesia: You will receive a local numbing injection at the insertion site, usually in a vein in your neck, arm, or groin ^{[1] [9]}. You will feel a quick pinch and burn, but after that, the area will be numb. You may feel some mild pressure as the catheter is inserted.
• During the Test: As the catheter passes through your heart, it is normal to experience brief palpitations, a fluttery feeling in your chest, or a cough.
• Sedation: Some patients receive mild sedation to help them relax. The medical team carefully monitors and adjusts this, as changes in breathing or deep sleep can alter the pressure readings ^[10].
• Duration: The procedure typically takes between 30 and 60 minutes depending on the access site used and whether extra tests are performed ^{[11] [12]}.

Vasoreactivity (Vasodilator) Testing

If you are being evaluated for idiopathic or heritable PAH, the doctor may perform a vasodilator challenge during the RHC. This involves giving you a fast-acting medication to see if your lung blood vessels relax and your pressures drop. This test identifies a small percentage of patients who might respond well to a specific class of drugs called calcium-channel blockers ^[13]. It is not used to test your response to all PAH medications.

What Exact Numbers Are They Looking For?

During the RHC, the doctor will measure pressures in the right side of your heart and your pulmonary artery ^[1]. According to the 2022 ESC/ERS guidelines, three specific measurements define a “precapillary” pulmonary hypertension pattern ^[4]:

1. mPAP (Mean Pulmonary Arterial Pressure): This must be greater than 20 mmHg ^[8].
2. PAWP (Pulmonary Arterial Wedge Pressure): This must be 15 mmHg or lower ^[8]. A low PAWP supports the conclusion that the high pressure in your lungs is not backing up from the left side of your heart ^[14].
3. PVR (Pulmonary Vascular Resistance): This measures how much resistance your heart faces when pumping blood into the lungs. It must be greater than 2 Wood units ^[15].

Your doctor will also measure your cardiac output (how much blood your heart is pumping) and right atrial pressure to assess how well your right heart is functioning ^{[16] [17]}.

Note: Having these numbers does not automatically mean you have PAH. A PAH diagnosis also requires completing your full clinical workup (like lung scans and breathing tests) to rule out other causes of pulmonary hypertension, such as lung disease or chronic blood clots ^[18].

Safety, Risks, and Recovery

Right heart catheterization is generally safe, especially when performed at an experienced pulmonary hypertension center, but it is an invasive procedure with some risks ^[9].

Possible Risks:
Common risks include bruising, bleeding, or a small hematoma (blood collection) at the insertion site ^[19]. Less commonly, patients may experience temporary abnormal heart rhythms, infection, or accidental injury to a blood vessel ^{[9] [20]}. Rare but serious complications, such as damage to the heart valves or pneumothorax (if a neck vein is used), can occur ^[21].

Recovery:
Recovery procedures depend on the access site and your clinic’s protocols. If the catheter was inserted into an arm or neck vein, you might be allowed to sit up and walk shortly after ^[22]. If a groin vein was used, you may need to lie flat for a few hours to prevent bleeding ^[23]. You will likely need someone to drive you home, especially if you received sedation. Always follow your specific care team’s instructions regarding when to restart blood thinners or other medications.

When to Seek Immediate Help:
After you go home, contact your care team or seek urgent medical care if you experience:

• Persistent or heavy bleeding at the insertion site
• Rapidly increasing swelling or a lump under the skin
• A cold, pale, or numb limb
• Fever, chills, or drainage from the site
• Worsening chest pain, shortness of breath, fainting, or sustained palpitations