Perioperative Cardiac Complications

Perioperative Cardiac Complications - Risk Radar On

• Goal: Identify & mitigate cardiac risk preoperatively.
• Revised Cardiac Risk Index (RCRI) components (1 point each):
  • High-risk surgery (e.g., vascular, intraperitoneal, intrathoracic)
  • Ischemic Heart Disease (IHD)
  • Congestive Heart Failure (CHF)
  • Cerebrovascular Disease (CVA)
  • Insulin-dependent Diabetes Mellitus
  • Serum Creatinine >2 mg/dL
• RCRI Score & MACE Risk: 0 pts ~0.4%; 1 pt ~0.9%; 2 pts ~6.6%; ≥3 pts ~11%.
• Functional Capacity: <4 METs (e.g., unable to climb 1 flight of stairs or walk 2 blocks) indicates ↑ risk.
• High risk (RCRI ≥2 or <4 METs) may need further evaluation (ECG, biomarkers, stress test) & optimization.

⭐ The Revised Cardiac Risk Index (RCRI) is a widely used tool to predict major adverse cardiac events (MACE); a score of ≥2 indicates elevated risk.

![Image placeholder: RCRI score components and MACE risk stratification]

Perioperative Cardiac Complications - Code Red Heart

• Perioperative Myocardial Infarction (PMI): Major risk.
  • Type 1 MI: Plaque rupture.
  • Type 2 MI: Supply-demand mismatch (common perioperatively).
  • Diagnosis: ↑ Troponin (rise/fall, one value >99th percentile URL) + ≥1 of:
    • Symptoms (often silent or atypical e.g., dyspnea, confusion).
    • ECG: New ST depression >1mm; ST elevation (e.g., >1mm in 2 contiguous leads); new LBBB.
    • Pathological Q waves.
    • Imaging: New wall motion abnormality / loss of viable myocardium.
  • Timing: Peaks 24-72h post-op.
• Other Complications:
  • Arrhythmias (e.g., Atrial Fibrillation, Ventricular Tachycardia).
  • Acute Heart Failure / Pulmonary Edema.
  • Hemodynamic instability (hypotension/hypertension).

⭐ Most perioperative myocardial infarctions (PMIs) are Type 2 MIs, often occurring postoperatively (within 48-72 hours) and may be clinically silent (detected by routine troponin monitoring).

Perioperative Cardiac Complications - Beat Goes Wrong

• Arrhythmias:
  • Most common: Atrial Fibrillation (AFib).

    ⭐ New-onset atrial fibrillation is the most common perioperative arrhythmia, often precipitated by surgical stress, pain, or electrolyte imbalance.

  • Types: SVT, VT, bradyarrhythmias.
  • Triggers: Stress, pain, hypoxia, electrolyte imbalance (K+, Mg++), ischemia.
  • Rx: Correct cause. Rate control (β-blockers), rhythm control (amiodarone, cardioversion if unstable), anticoagulation.
• Myocardial Ischemia/Infarction (MI):
  • Risk: CAD, HTN, DM, LVEF <40%, age >65.
  • Triggers: ↑O₂ demand (tachycardia) or ↓supply (hypotension, anemia).
  • Dx: ECG (ST changes), ↑troponins.
  • Rx: MONA-B (Morphine, Oxygen, Nitrates, Aspirin, β-blockers). Cardiology consult.
• Heart Failure (HF) / Pulmonary Edema:
  • Causes: Fluid overload, MI, arrhythmias.
  • Symptoms: Dyspnea, crackles, JVD, desaturation.
  • Rx: LMNOP (Lasix, Morphine, Nitrates, Oxygen, Position-upright).

Perioperative Cardiac Complications - Guarding the Engine

• Risk Stratification: Utilize RCRI (Revised Cardiac Risk Index) to predict MACE. Key factors: high-risk surgery, ischemic heart disease, CHF, CVA, insulin-dependent DM, Cr >2 mg/dL.
• Preventative Strategies:
  • Beta-blockers: Continue if already on. Cautious initiation for high-risk surgery if ≥3 RCRI factors.
  • Statins: Indicated for vascular surgery patients.
  • Aspirin: Continue for established CAD unless bleeding risk is prohibitive.
  • Glycemic control: Target glucose <180 mg/dL.
• Intraoperative Management:
  • Maintain hemodynamic stability: MAP >65 mmHg, avoid tachycardia/hypotension.
  • Continuous ECG monitoring for ischemia (ST depression/elevation) and arrhythmias.
• Postoperative Care: Vigilant monitoring, pain control, DVT prophylaxis.

⭐ Perioperative beta-blocker therapy should be continued in patients already receiving it; cautious initiation may be considered in high-risk patients undergoing high-risk surgery, but not routinely.

High‑Yield Points - ⚡ Biggest Takeaways

• Perioperative MI: leading cause of death; ECG changes (ST depression) & troponin rise are diagnostic.
• Major risk factors: IHD, CHF, DM, CKD, high-risk surgery.
• RCRI stratifies risk; >2 points = high risk.
• Continue beta-blockers; consider for high-risk patients.
• Avoid intraoperative hypotension & tachycardia to prevent cardiac events.
• Postoperative AF is common (esp. thoracic surgery); manage rate/rhythm.
• Demand ischemia (Type 2 MI) is more common perioperatively than Type 1 MI.