What are the EKG findings and treatment options for a patient with aortic regurgitation?

EKG Findings in Aortic Regurgitation

The EKG in aortic regurgitation primarily shows left ventricular hypertrophy with or without strain pattern, and these findings correlate directly with disease severity and left ventricular dysfunction. 1

Primary EKG Abnormalities

Left Ventricular Hypertrophy

• Increased QRS voltage is the hallmark finding, reflecting the chronic volume overload and compensatory left ventricular enlargement that develops in AR 2, 1
• The presence and magnitude of voltage criteria correlate with echocardiographic left ventricular mass (431 ± 138 g in patients with abnormal findings versus 303 ± 89 g in those with normal tracings) 1

Repolarization Abnormalities ("Strain Pattern")

• The strain pattern (ST depression and T wave inversion in lateral leads) is a critical marker of advanced disease 1
• Patients with strain pattern demonstrate:
  • Greater left ventricular end-diastolic dimensions (7.2 ± 1.1 cm versus 6.6 ± 0.8 cm) 1
  • Greater left ventricular end-systolic dimensions (5.2 ± 1.2 cm versus 4.4 ± 0.7 cm) 1
  • Higher end-systolic wall stress (128 ± 46 versus 95 ± 27 dynes-cm² × 10³) 1
  • Lower fractional shortening (28 ± 8% versus 34 ± 5%) 1
  • Lower exercise ejection fraction (39 ± 11% versus 51 ± 8%) 1

Left Atrial Abnormality

• Enlargement or overloading of the left atrium may be detected, reflecting elevated left ventricular end-diastolic pressures in advanced disease 2

Rhythm and Conduction Disturbances

• Atrial fibrillation is an independent predictor of mortality (P=0.002) and indicates advanced disease 3, 2
• Bundle branch blocks may develop with progressive left ventricular dilation 2
• AV conduction abnormalities (first through third degree block) can occur 2
• Supraventricular and ventricular extrasystoles may be present 2

Clinical Significance of EKG Findings

The strain pattern identifies high-risk patients even when asymptomatic, with significantly higher prevalence of:

• Fractional shortening <25% (5 of 27 versus 1 of 45 patients) 1
• Left ventricular systolic dimension >5.5 cm (8 of 27 versus 1 of 45 patients) 1

Multiple logistic regression demonstrates that left ventricular mass and end-systolic stress independently predict repolarization abnormalities (p <0.005) 1

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Treatment Approach for Aortic Regurgitation

Severity Assessment First

Use an integrative, multi-parametric echocardiographic approach—no single parameter determines severity 4, 5

Severe AR Criteria (any of the following):

• Vena contracta ≥6 mm 6
• Effective regurgitant orifice area (EROA) ≥30 mm² 6
• Regurgitant volume ≥60 mL 6
• Pressure half-time <200 ms 6
• Holodiastolic flow reversal in descending aorta with end-diastolic velocity >20 cm/s 6
• Flail valve or large coaptation defect 6

Moderate AR Criteria:

• Vena contracta 0.3-0.6 cm 4
• EROA 0.10-0.29 cm² 4
• Regurgitant volume 30-59 mL/beat 4
• Regurgitant fraction 30-49% 4

Mild AR Criteria:

• Vena contracta <0.3 cm 4
• EROA <0.10 cm² 4
• Regurgitant volume <30 mL/beat 4

Surgical Intervention Indications

Surgery is the definitive treatment and should be performed promptly in high-risk patients to reduce cardiovascular mortality (adjusted hazard ratio 0.54, P=0.048) 3

Class I Indications for Surgery:

• Any symptoms attributable to AR (even mild class II symptoms carry 6.3% yearly mortality) 4, 3
• Left ventricular ejection fraction ≤55% (asymptomatic patients with LVEF <55% have 5.8% yearly mortality) 4, 3
• Left ventricular end-systolic diameter ≥25 mm/m² body surface area (7.8% yearly mortality risk) 3
• Patients undergoing cardiac surgery for another indication (consider concomitant valve surgery even with moderate AR) 4

Preoperative Coronary Evaluation:

• Coronary angiography is mandatory for all elderly patients (particularly >70 years) with severe AR prior to surgery 7
• CT imaging can evaluate both coronary anatomy and aortic pathology simultaneously 7
• Allows for combined CABG and aortic valve replacement when indicated 7

Medical Management

Asymptomatic Patients with Normal LV Function:

• No specific medical therapy required 4
• Surveillance echocardiography every 3-5 years for mild AR, every 1-2 years for moderate AR 4
• More frequent monitoring (every 3-6 months) if increasing LV size or decreasing LV function 4

Asymptomatic Patients with Severe AR and LV Dilation:

• Nifedipine is the best evidence-based vasodilator to potentially prolong the compensated phase and delay surgery 8
• ACE inhibitors are particularly useful for hypertensive patients with AR 4, 8

Symptomatic Patients or LV Dysfunction:

• Vasodilators only as short-term bridge to surgery if severe heart failure is present 8
• Surgery should not be delayed—medical therapy does not substitute for timely intervention 8

Special Populations:

• Beta-blockers may slow aortic root dilation in patients with AR associated with aortic root disease 8
• Beta-blockers may improve cardiac performance post-AVR in patients with impaired LV function 8

Critical Pitfalls to Avoid

• Do not rely on a single echocardiographic parameter—use the integrative approach outlined above 4, 5
• Do not miss aortic root or ascending aorta dilation, which requires more frequent monitoring 4
• Do not delay surgery in patients with transient severe symptoms (24.6% yearly mortality) 3
• Recognize that even mild symptoms (class II) carry excess mortality (6.3% yearly) and warrant consideration for surgery 3
• Factors associated with rapid progression include bicuspid aortic valve, rheumatic disease, and aortic root dilation—these patients need closer surveillance 4

Natural History Context

Conservatively managed severe AR carries mortality rates higher than expected (34 ± 5% at 10 years, P<0.001), with 10-year rates of 47 ± 6% for heart failure and 62 ± 4% for requiring surgery 3. At 10 years, 75 ± 3% of patients had died or undergone surgery, and 83 ± 3% had cardiovascular events 3. This underscores the serious prognosis and need for timely intervention.