What is the management approach for biventricular hypertrophy?

Management of Biventricular Hypertrophy

The management of biventricular hypertrophy should focus on treating the underlying cause, controlling symptoms, and preventing complications through a combination of medical therapy, risk factor modification, and in selected cases, surgical intervention. 1

Diagnostic Evaluation

• Comprehensive cardiac imaging with echocardiography is essential to confirm biventricular hypertrophy, assess the degree of obstruction, and evaluate for associated abnormalities such as mitral valve dysfunction 1
• Cardiac MRI should be considered to better characterize the extent of hypertrophy, detect fibrosis, and assess for iron overload, particularly in cases with unclear diagnosis 1
• Electrocardiographic monitoring is recommended to detect conduction abnormalities and arrhythmias, which are common complications 1

Medical Management

First-Line Pharmacological Therapy

• Non-vasodilating beta-blockers titrated to maximum tolerated dose are the first-line treatment for symptomatic biventricular hypertrophy, particularly when left ventricular outflow tract obstruction (LVOTO) is present 1
• Calcium channel blockers (verapamil starting at 40mg three times daily to maximum 480mg daily, or diltiazem starting at 60mg three times daily to maximum 360mg daily) should be considered in patients who are intolerant or have contraindications to beta-blockers 1
• If beta-blockers alone are ineffective, disopyramide (titrated up to 400-600 mg/day) may be added to improve symptoms by reducing outflow tract gradients 1

Cautions and Contraindications

• Arterial and venous dilators, including nitrates and phosphodiesterase inhibitors, should be avoided in patients with resting or provocable LVOTO as they can worsen obstruction 1
• Digoxin is contraindicated in patients with LVOTO due to its positive inotropic effects 1
• Dihydropyridine calcium channel blockers (e.g., nifedipine) are not recommended for LVOTO 1
• Low-dose loop or thiazide diuretics may be used cautiously to improve dyspnea, but hypovolemia must be avoided 1

Management of Specific Complications

Atrial Fibrillation

• Prompt restoration of sinus rhythm or appropriate rate control is essential in patients with new-onset or poorly controlled atrial fibrillation, as it can exacerbate symptoms 1
• Patients with biventricular hypertrophy may have poor tolerance of atrial fibrillation due to greater dependency on atrial systole for ventricular filling 1

Heart Failure

• Heart failure is the most common presenting symptom in certain forms of biventricular hypertrophy, such as Barth syndrome 1
• Standard heart failure management should be implemented, with careful consideration of medications that might worsen outflow tract obstruction 1

Invasive Treatment Options

• Surgical intervention should be considered for patients with severe symptoms refractory to medical therapy 2, 3
• For left ventricular obstruction, extended septal myectomy via a transaortic approach is the standard surgical procedure 1, 3
• Right ventricular outflow tract obstruction can be relieved with patch enlargement and selective resection of muscle bundles 2, 3
• Concomitant mitral valve surgery may be required in 11-20% of patients undergoing myectomy 1
• Septal alcohol ablation is an alternative to surgery in selected patients, but requires careful patient selection and experienced centers 1

Risk Factor Modification

• Intensive management of cardiometabolic risk factors is essential, as obesity, hypertension, diabetes, and sleep apnea are highly prevalent in patients with hypertrophic cardiomyopathy and associated with poorer prognosis 1
• For hypertension-related biventricular hypertrophy, ARBs (particularly losartan) or ACE inhibitors are preferred first-line agents for regression of left ventricular mass 4, 5
• Aldosterone antagonists have shown efficacy equal to ACE inhibitors in reducing left ventricular hypertrophy 4

Follow-up and Monitoring

• Regular cardiac evaluation is warranted regardless of neurological status in patients with certain conditions like Friedreich's ataxia 1
• Monitoring should include assessment of symptom progression, cardiac function, and arrhythmia surveillance 1
• Exercise testing may be of limited utility in some forms of biventricular hypertrophy due to significant limitations from both cardiac and skeletal muscle impairments 1

Prognosis and Outcomes

• With appropriate surgical intervention, symptoms of biventricular obstruction can be significantly improved with good intermediate-term outcomes 2, 3
• Surgical relief of biventricular obstruction has been associated with low rates of ventricular arrhythmias, sudden deaths, and need for heart transplantation at intermediate follow-up 3
• Treatment-induced regression of left ventricular hypertrophy is independently associated with reduction in major cardiovascular events, stroke, and mortality 4