Interpreting Cardiac Catheterization

Documents to Request

• Full catheterization report with angiographic images
• Hemodynamic tracings (pressure waveforms)
• Prior catheterization reports for comparison
• Non-invasive testing results (stress echo, nuclear, CCTA)
• Echocardiogram (for valve correlation)
• Current medication list (antiplatelet, anticoagulant)
• Labs: BMP, CBC, coagulation studies, troponin trend if ACS

Step 1: Hemodynamic Data Interpretation

Normal Resting Hemodynamic Values:

Key Hemodynamic Calculations:

• Cardiac output (Fick) = VO₂ / (1.36 × Hgb × 10 × [SaO₂ − SvO₂])
• SVR = (MAP − RAP) × 80 / CO
• PVR = (mPAP − PCWP) × 80 / CO
• Valve area (Gorlin formula): AVA = CO / (44.3 × SEP × HR × √mean gradient)

Hemodynamic Pattern Recognition:

Step 2: Coronary Angiography Interpretation

Standard Coronary Anatomy Reporting:

• Left main (LM): length, caliber, disease
• Left anterior descending (LAD): proximal, mid, distal segments; diagonal branches (D1, D2)
• Left circumflex (LCx): proximal, distal; obtuse marginal branches (OM1, OM2)
• Right coronary artery (RCA): proximal, mid, distal; posterior descending (PDA), posterolateral (PLV)
• Dominance: right-dominant (85%), left-dominant (8%), co-dominant (7%)

Lesion Severity Classification:

Physiologic Assessment:

• FFR (fractional flow reserve): ≤ 0.80 = hemodynamically significant
• iFR (instantaneous wave-free ratio): ≤ 0.89 = significant
• IVUS/OCT: used for plaque characterization, stent optimization, left main assessment

Lesion Morphology (ACC/AHA Classification):

• Type A: discrete (< 10 mm), concentric, non-calcified → high PCI success
• Type B1: tubular (10–20 mm), eccentric, moderate calcification → moderate risk
• Type B2: two or more Type B features → higher risk
• Type C: diffuse (> 20 mm), total occlusion, degenerated graft → highest risk

Step 3: PCI Documentation (If Intervention Performed)

Document each intervention with:

1. Target vessel and segment
2. Lesion characteristics (length, calcification, bifurcation involvement)
3. Pre-intervention stenosis percentage
4. Guidewire and catheter used
5. Pre-dilation details (balloon size, pressure, result)
6. Stent deployed (DES type, dimensions, deployment pressure)
7. Post-dilation (if performed)
8. Final angiographic result (residual stenosis, TIMI flow grade)
9. Complications (dissection, perforation, no-reflow, side branch loss)

TIMI Flow Grading:

Step 4: Ventriculography and Additional Findings

LV Function by Ventriculography:

• Qualitative: normal, mild/moderate/severe hypokinesis, akinesis, dyskinesis
• LVEF estimation from RAO 30° projection
• Wall motion abnormalities mapped to coronary territories

Additional Assessments:

• Aortography: aortic regurgitation grading (1+ to 4+), aortic root dimensions
• Shunt assessment: step-up in O₂ saturation (Qp:Qs > 1.5 = significant L→R shunt)
• Transplant evaluation: right heart hemodynamics, PVR calculation, vasoreactivity testing

Step 5: Post-Procedure Assessment and Complications

Immediate Post-Cath Monitoring:

• Access site: hematoma, retroperitoneal bleed, pseudoaneurysm, AV fistula
• Renal: contrast-induced nephropathy risk (hydrate; check Cr at 48–72 hours)
• Vascular: limb ischemia if femoral approach, radial artery occlusion
• Cardiac: post-PCI chest pain, stent thrombosis, coronary dissection

Dual Antiplatelet Therapy (DAPT) Post-PCI:

• After DES: aspirin + P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel)
• ACS: minimum 12 months DAPT
• Stable CAD: minimum 6 months DAPT (3 months in high bleeding risk)
• Triple therapy (DOAC + DAPT) if concurrent AF: minimize duration; de-escalate to DOAC + single antiplatelet

Checkpoint B: Post-Draft Alignment (Mandatory)

1. Are all hemodynamic values documented with normal references?
2. Is every coronary artery segment reported with dominance stated?
3. For PCI: is the lesion, device, and result fully documented with TIMI flow?
4. Are complications assessed and documented or their absence noted?
5. Is the post-procedure antiplatelet plan specified with duration?

Quality Audit

• Indication for catheterization clearly stated
• Vascular access site and technique documented
• Complete hemodynamic data with normal reference ranges
• Coronary dominance identified
• All coronary arteries and major branches described
• Lesion severity quantified (%) for each stenosis
• FFR/iFR reported for intermediate lesions (50–70%)
• PCI details complete: lesion, equipment, stent specs, final result
• TIMI flow grade documented pre- and post-intervention
• LV function assessed (by ventriculography or prior echo)
• Complications listed or "no complications" explicitly stated
• Contrast volume documented (nephropathy risk)
• Post-procedure medication plan (DAPT) documented
• Comparison with prior catheterization if available

Guidelines

1. Report coronary dominance in every catheterization interpretation — it affects the clinical significance of RCA vs. LCx lesions.
2. Intermediate stenoses (50–69%) should trigger documentation of whether physiologic assessment (FFR/iFR) was performed or planned.
3. For left main disease ≥ 50%, always document referral to Heart Team discussion for CABG vs. PCI per ACC/AHA guidelines.
4. Hemodynamic waveforms should be correlated with clinical context — giant V waves on PCWP tracing must be reported and correlated with MR severity on echo.
5. Contrast volume should be documented and kept below 3–4× eGFR to minimize nephropathy risk.
6. When CTO is identified, document the presence and grade of collateral supply (Rentrop classification).
7. Post-PCI DAPT duration must account for bleeding risk, ischemic risk, and concurrent anticoagulation needs — document the rationale for chosen duration.