What is the recommended peri‑operative management of arrhythmias for a patient over 60 years old with hypertension, coronary artery disease, diabetes and chronic atrial fibrillation, including pre‑operative medication review, electrolyte optimization, intra‑operative monitoring, treatment of atrial fibrillation/flutter, symptomatic bradyarrhythmias, ventricular tachycardia, and post‑operative care?

Perioperative Arrhythmia Management in High-Risk Patients

For a patient over 60 with hypertension, coronary artery disease, diabetes, and chronic atrial fibrillation undergoing noncardiac surgery, maintain chronic rate-control medications perioperatively, bridge anticoagulation based on thromboembolic risk, use beta-blockers as first-line for rate control, and aggressively correct underlying causes before treating any new arrhythmias pharmacologically. 1

Pre-operative Medication Review

Chronic Atrial Fibrillation Management

• Continue chronic rate-control medications (beta-blockers, diltiazem, or verapamil) through the morning of surgery—do not discontinue these agents as abrupt withdrawal increases perioperative arrhythmia risk. 1

• Beta-blockers (atenolol, metoprolol) are the most effective agents for controlling ventricular response during atrial fibrillation at rest and during exercise; diltiazem and verapamil are acceptable alternatives. 1

• Digoxin is only effective for rate control at rest and should be used as a second-line agent; it is the least effective option for perioperative rate control. 1

• Prophylactic beta-blocker therapy should be instituted in patients at increased risk of developing perioperative arrhythmias, as this reduces mortality and cardiovascular complications including arrhythmias during surgery and up to 2 years afterward. 1

Anticoagulation Bridging Strategy

• Discontinue warfarin 5 days before surgery to allow INR to normalize to ≤1.5 for procedures with moderate-to-high bleeding risk. 1

• Bridging anticoagulation with low-molecular-weight heparin or unfractionated heparin is recommended for patients at high thromboembolic risk: mechanical mitral valve, recent (<1 year) thromboembolism, or ≥3 risk factors (atrial fibrillation, prior embolus, hypercoagulable state, mechanical prosthesis, LVEF <30%). 1

• For patients between high and low risk extremes, assess individual thromboembolic risk (CHA₂DS₂-VASc score ≥4) versus bleeding risk to determine bridging necessity. 1

• If urgent surgery is required and warfarin effect must be reversed immediately, administer parenteral vitamin K or fresh frozen plasma. 1

Electrolyte Optimization

• Measure and correct serum potassium and magnesium preoperatively—target potassium >4.0 mEq/L and magnesium >2.0 mg/dL, as deficiencies predispose to both atrial and ventricular arrhythmias. 1, 2, 3

• Recheck electrolytes on the morning of surgery, particularly in patients taking diuretics or with renal dysfunction. 1

• Avoid aggressive acute potassium repletion in asymptomatic patients, as this may pose greater risk than benefit. 2

Intra-operative Monitoring and Management

Standard Monitoring

• Continuous 12-lead ECG monitoring is sufficient for patients with chronic atrial fibrillation or premature ventricular contractions—no additional invasive hemodynamic monitoring is required solely because of pre-existing arrhythmias. 1, 2

• Monitor for new ST-segment changes indicating myocardial ischemia, as atrial fibrillation and supraventricular arrhythmias increase myocardial oxygen demand and can produce ischemia in patients with coronary disease. 1

Treatment Principles for Intra-operative Arrhythmias

• Search for and correct underlying causes first: hypoxemia, myocardial ischemia, catecholamine excess, electrolyte abnormalities, drug toxicity, or metabolic derangements before initiating antiarrhythmic therapy. 1, 4, 5

• Maintain adequate depth of anesthesia and stable hemodynamics to limit sympathetic stimulation that exacerbates arrhythmias. 2

Atrial Fibrillation/Flutter Management

• For rapid ventricular response in chronic atrial fibrillation, use intravenous beta-blockers as first-line therapy (esmolol or metoprolol). 1

• Intravenous diltiazem is the second-line agent when beta-blockers are contraindicated or inadequate; however, beta-blockers are more effective and accelerate conversion of postoperative supraventricular arrhythmias to sinus rhythm compared with diltiazem. 1

• Intravenous digoxin or amiodarone can be used for acute rate control when beta-blockers and calcium channel blockers are contraindicated (e.g., decompensated heart failure, hypotension). 1

• Electrical cardioversion is indicated for sustained supraventricular arrhythmias causing hemodynamic instability; pharmacological cardioversion with ibutilide is reasonable for postoperative atrial fibrillation in stable patients. 1

• Do not use nondihydropyridine calcium channel blockers, beta-blockers, or dronedarone in patients with decompensated heart failure or hypotension. 1

Ventricular Arrhythmia Management

• Asymptomatic premature ventricular contractions, complex ventricular ectopy, and nonsustained ventricular tachycardia do not require treatment unless they cause hemodynamic compromise—these arrhythmias are not associated with increased risk of nonfatal MI or cardiac death in the perioperative period. 1, 2

• Intravenous beta-blockers are first-line therapy for symptomatic ventricular arrhythmias causing hemodynamic instability. 1, 2

• For refractory ventricular arrhythmias, use intravenous lidocaine, procainamide, or amiodarone as second-line agents. 1, 2

• Immediate electrical cardioversion is indicated for sustained ventricular tachycardia with hemodynamic compromise. 1, 2

• Sustained or symptomatic ventricular tachycardia should be suppressed with intravenous lidocaine, procainamide, or amiodarone, followed by a thorough search for underlying causes (ischemia, electrolyte abnormalities, drug toxicity). 1, 2

Symptomatic Bradyarrhythmias

• Temporary transvenous pacing wires (if placed during cardiac surgery) can manage transient bradyarrhythmias in the immediate postoperative period. 1

• Patients with intraventricular conduction delays, bifascicular block, or left bundle-branch block do not require temporary pacemaker implantation in the absence of syncope or documented high-grade atrioventricular block. 1

• High-grade cardiac conduction abnormalities (complete atrioventricular block) may necessitate temporary or permanent transvenous pacing if unanticipated and symptomatic. 1

Post-operative Care

Continued Monitoring

• Standard cardiac monitoring in the immediate postoperative period is sufficient—no special surveillance is required solely for pre-existing arrhythmias. 2

• Recheck electrolytes (potassium, magnesium) in the postoperative period and correct deficiencies to reduce recurrent ectopy risk. 2, 3

New-Onset Arrhythmias

• Postoperative atrial fibrillation peaks 1-3 days after surgery and is often self-limiting; manage with rate control (beta-blockers preferred) and consider anticoagulation based on CHA₂DS₂-VASc score and bleeding risk. 1, 3, 6

• Beta-blockers reduce the incidence of postoperative atrial fibrillation and should be continued or initiated in high-risk patients. 1, 4

• Amiodarone is reasonable for rhythm maintenance in select patients whose quality of life is compromised by recurrent atrial fibrillation, but most patients should not be placed on rhythm maintenance therapy as risks outweigh benefits. 1

• Anticoagulation for postoperative atrial fibrillation should be used cautiously due to transient nature and excessive bleeding risk immediately post-surgery; base decisions on CHA₂DS₂-VASc score and surgical bleeding risk. 1, 6

Ventricular Arrhythmia Follow-up

• Patients who develop sustained or nonsustained ventricular tachycardia perioperatively require cardiology referral for evaluation of ventricular function and screening for coronary artery disease. 1, 2

• Patients with ischemic or nonischemic cardiomyopathy, LVEF <35%, heart failure, and perioperative nonsustained ventricular tachycardia should be assessed for implantable cardioverter-defibrillator therapy for primary prevention. 2

Anticoagulation Resumption

• Resume warfarin on postoperative day 1 (evening of surgery or next morning) if hemostasis is adequate and bleeding risk is acceptable. 1, 7

• Continue bridging anticoagulation until INR returns to therapeutic range (2.0-3.0) for patients who required bridging preoperatively. 1, 7

Critical Pitfalls to Avoid

• Do not discontinue chronic beta-blockers or rate-control medications preoperatively—abrupt withdrawal increases arrhythmia risk and adverse cardiovascular events. 1

• Do not treat asymptomatic ventricular arrhythmias with antiarrhythmic drugs—routine suppression is not evidence-based and may increase medication-related risk without reducing perioperative cardiac events. 1, 2

• Do not use rate-controlling medications as first-line therapy for sinus tachycardia—aggressively identify and correct underlying causes (pain, hypovolemia, infection, hypoxemia, electrolyte abnormalities) first. 3

• Do not add aspirin to warfarin in patients with valvular atrial fibrillation—this increases bleeding risk without demonstrable benefit. 7

• Do not delay surgery solely because of asymptomatic premature ventricular contractions or chronic stable atrial fibrillation—these findings do not independently increase perioperative mortality when rate is controlled. 1, 2

• Do not miss ongoing surgical complications (anastomotic leak, intra-abdominal abscess) when evaluating postoperative tachycardia—fever combined with tachycardia strongly suggests infection requiring immediate broad-spectrum antibiotics. 3