How to manage impaired diastolic function?

Management of Impaired Diastolic Function

Treatment of diastolic dysfunction should target underlying causes and focus on controlling heart rate, blood pressure, and volume status, with beta-blockers, ACE inhibitors, and cautious use of diuretics as the cornerstone of therapy. 1

Understanding Diastolic Dysfunction

Diastolic dysfunction occurs when the heart's ability to relax and fill adequately is impaired, leading to elevated filling pressures despite normal ejection fraction. It is characterized by:

• Impaired ventricular relaxation
• Decreased left ventricular compliance
• Elevated left atrial pressure
• Normal or near-normal systolic function

Diastolic dysfunction is common in elderly patients, particularly women with hypertension, and can significantly impact quality of life through symptoms of dyspnea, fatigue, and exercise intolerance 1.

Diagnostic Approach

The American Society of Echocardiography recommends evaluating:

• E/e' ratio (>14 suggests elevated filling pressures)
• Left atrial volume index (>34 mL/m²)
• Tricuspid regurgitation velocity (>2.8 m/sec)
• Pulmonary vein atrial reversal velocity 1

Diastolic dysfunction is graded from I to III, with increasing severity correlating with worse prognosis 2.

Treatment Algorithm

1. Identify and Treat Underlying Causes

• Hypertension (primary target, present in ~90% of cases)
• Coronary artery disease (consider revascularization if ischemia is present) 1
• Diabetes
• Obesity
• Sleep apnea

2. Pharmacological Management

First-line therapy:

• ACE inhibitors/ARBs: Improve relaxation, reduce hypertrophy, and decrease blood pressure 1, 2
• Beta-blockers: Lower heart rate to increase diastolic filling period 1

Second-line options:

• Verapamil-type calcium channel blockers: May improve relaxation and functional capacity, especially in hypertrophic cardiomyopathy 1, 3
• Diuretics: For fluid overload, but use cautiously to avoid excessive preload reduction 1

For specific situations:

• Rate control medications: For patients with atrial fibrillation to optimize diastolic filling 1
• Anticoagulation: For patients with atrial fibrillation or previous embolization 1

3. Blood Pressure Management

• Target <130/80 mmHg 2
• Prioritize ACE inhibitors or ARBs as first-line agents

4. Lifestyle Modifications

• Sodium restriction
• Weight loss for obese patients
• Treatment of sleep apnea if present
• Regular monitoring for progression of dysfunction

Important Considerations and Pitfalls

• Avoid excessive diuresis: Diastolic dysfunction patients are preload-dependent; excessive diuresis can reduce stroke volume and cardiac output 1
• Avoid positive inotropic agents: Generally not useful as systolic function is preserved 1
• Monitor for hypotension: Start with small doses of medications and titrate carefully 1
• Recognize mixed dysfunction: Pure diastolic dysfunction is rare; many patients have some degree of systolic dysfunction as well 1
• Consider comorbidities: Elderly patients often have multiple conditions requiring careful medication management 1

Prognosis

The mortality risk increases with the grade of diastolic dysfunction:

• Normal diastolic function: 95% survival
• Grade I dysfunction: 79% survival
• Grade II dysfunction: 39% survival 2

Regular monitoring is essential as diastolic dysfunction can progress over time, and early intervention may prevent development of overt heart failure symptoms.