Right Heart Catheterization (RHC) is a critical tool for diagnosing and managing various cardiovascular and pulmonary conditions. This invasive hemodynamic assessment provides real-time insight into the function and pressures of the right heart, pulmonary arteries, and left heart indirectly via the pulmonary capillary wedge pressure (PCWP).
Here’s a streamlined breakdown of RHC interpretation essentials:
🔍 Direct Measurements
- CVP (Central Venous Pressure)
- RA, RV, PA, PCWP: Right-sided pressures
- CO (Cardiac Output)
- SvO₂ (Mixed Venous O2 Saturation)
📉 Indirect Calculations
- SVR (Systemic Vascular Resistance) = 80 × [(MAP – CVP) / CO]
- PVR (Pulmonary Vascular Resistance) = 80 × [(mean PAP – PCWP) / CO]
- CI (Cardiac Index) = CO / BSA
- SVI (Stroke Volume Index) = CI / HR
- O₂ Delivery = CI × 13.4 × Hb × SaO₂
📊 RA Waveform Interpretation
- Normal waveform includes a, c, and v waves with x and y descents.
- Abnormal waveforms:
- Tall v waves: Tricuspid regurgitation
- Cannon a waves: AV dissociation
- Blunted y descent: Cardiac tamponade
- Prominent x/y descents: Restrictive or constrictive pathology
- Absent a wave: Atrial fibrillation
🫀 RV Pressures & Waveforms
- Normal RV systolic: 15–25 mmHg
- RV end-diastolic: 3–12 mmHg
- Elevated RVSP can indicate pulmonary hypertension, PE, or pulmonic stenosis.
- Elevated RVEDP suggests RV ischemia, tamponade, or cardiomyopathy.
🌬 PA Pressures & Waveforms
- PASP: 15–25 mmHg | PADP: 8–15 mmHg
- Mean PAP: 16–22 mmHg
- The dicrotic notch marks closure of the pulmonic valve.
- Useful for classifying pulmonary hypertension by WHO groups.
🫁 PCWP Pressures & Waveforms
- Reflects LA pressure and LV compliance
- Normal wedge: ~9 mmHg (6–15 range)
- Large a waves: LV diastolic dysfunction, mitral stenosis
- Large v waves: Mitral regurgitation or sudden LA volume increase (e.g., VSD)
🧠 Final Thoughts
Right Heart Catheterization can unlock vital diagnostic clues. From subtle waveform changes to pressure elevations, careful interpretation informs treatment of heart failure, pulmonary hypertension, and valvular diseases. This cheat sheet offers a visual snapshot—ideal for bedside review or board prep.
📌 Pro Tip: Always interpret pressures and waveforms in the context of clinical findings and echocardiographic correlation.