Is the current management plan appropriate for a 51-year-old male with apical hypertrophic cardiomyopathy (apHCM), also known as 'Yamaguchi syndrome', who presents with symptomatic monomorphic nonsustained ventricular tachycardia (NSVT) and a history of syncope, hypertension (HTN), diabetes mellitus (DM), and other comorbidities?

From the Guidelines

The current plan for this 51-year-old male with apical hypertrophic cardiomyopathy (Yamaguchi syndrome) who presented with symptomatic non-sustained ventricular tachycardia (NSVT) is inadequate and requires immediate modification to prioritize his high-risk features and prevent sudden cardiac death. The patient's presentation with symptomatic NSVT, syncope, family history of HCM, and symptoms during arrhythmia warrants aggressive management.

Key Considerations

• The patient has multiple concerning features that increase his risk for sudden cardiac death, including syncope and symptomatic NSVT, which are major risk factors according to the 2017 AHA/ACC/HRS guideline for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 1.
• The 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline for the management of hypertrophic cardiomyopathy emphasizes the importance of shared decision-making, careful ascertainment of family history, and assessing a patient's risk for sudden cardiac death 1.
• The patient's inability to undergo CMR due to claustrophobia presents a diagnostic challenge that could be addressed with alternative imaging strategies such as contrast echocardiography or CT.

Management Recommendations

• Immediate hospitalization for cardiac monitoring and comprehensive risk stratification is essential to determine the best course of treatment and prevent sudden cardiac death.
• Consideration for ICD placement is warranted given the patient's high-risk features, as recommended by the 2017 AHA/ACC/HRS guideline 1.
• Medication therapy should include initiating or optimizing beta-blocker therapy, such as metoprolol 25-50mg twice daily, to reduce arrhythmia burden and symptoms. If beta-blockers are contraindicated or insufficient, non-dihydropyridine calcium channel blockers like verapamil 120-360mg daily in divided doses could be considered.
• Antiarrhythmic therapy with amiodarone may be necessary if ventricular arrhythmias persist despite beta-blockade.

Teaching Points for Cardiology Fellows

• The importance of comprehensive risk stratification in HCM patients for sudden cardiac death, including evaluating five major risk factors: family history of sudden death, unexplained syncope, massive LVH (≥30mm), NSVT on ambulatory monitoring, and abnormal blood pressure response during exercise.
• The presence of multiple risk factors compounds risk exponentially rather than additively, and fellows should understand how to assess and manage this risk.
• Apical HCM (Yamaguchi syndrome) typically has a more benign course than other HCM variants, but the presence of arrhythmias and syncope in this patient suggests a higher-risk phenotype requiring more aggressive management.

From the Research

Assessment of the Plan

• The patient's history of apHCM ("Yamaguchi syndrome"), syncope, and nonsustained ventricular tachycardia (NSVT) suggests a high risk of sudden cardiac death (SCD) 2, 3, 4.
• The presence of NSVT, particularly with a high heart rate and long duration, is a significant predictor of appropriate ICD therapy and SCD in patients with hypertrophic cardiomyopathy (HCM) 2, 3.
• The patient's recent symptoms of chest pain, shortness of breath, severe palpitations, dizziness, and near-syncope, in the absence of signs of acute coronary syndrome, suggest that the symptoms are related to apHCM.

Teaching Points for Cardiology Fellows

• NSVT is a significant risk factor for SCD in patients with HCM, particularly in young patients 4.
• The characteristics of NSVT, such as heart rate and duration, can predict the risk of SCD and appropriate ICD therapy 2, 3.
• The use of implantable cardioverter-defibrillators (ICDs) can be effective in preventing SCD in high-risk patients with HCM 2, 3, 5.
• The assessment of new ultrasonic derived parameters, such as tissue synchronization imaging and two-dimensional strain, can help identify patients with HCM at higher risk for NSVT 6.
• A comprehensive evaluation of patients with HCM, including clinical history, echocardiography, and ambulatory monitoring, is essential for risk stratification and management 2, 3, 5, 4, 6.