Obstructive Hypertrophic Cardiomyopathy Kenneth M. Kent, M.D. Washington Hospital Center Washington, D.C.

Kenneth M. Kent, MD I have no real or apparent conflicts of interest to report.

Baseline LV apex/ Aorta

Obstructive Hypertrophic Cardiomyopathy Uncommon, 1 – 2 % population Genetic abnormality Symptoms appear at any age, greater risk of complications at earlier age Obstructive: ≥ 60 mmHg at rest or provocation Natural history with mild symptoms or post septal reduction procedures 1 – 3% mortality/year

Obstructive Hypertrophic Cardiomyopathy Risk Stratification: LV mass, wall thickness, family history, age onset of symptoms, severity of symptoms (exercise tolerance) Progression from Obstructive to Non Obstructive HCM is not uncommon either with or without septal reduction procedures.

Obstructive Hypertrophic Cardiomyopathy Alcohol Septal Ablation (Patient Selection) Indication: Symptom relief not prevention of sudden death, simply reduction of gradient, allow unrestricted activity, prolong life Thus: candidates must have Class II to III symptoms despite maximum medical therapy which should include adequate doses of beta blocking agents and verapamil/diltiazem

Obstructive Hypertrophic Cardiomyopathy Alcohol Septal Ablation Canulate first septal artery, selectively isolate the distribution with balloon catheter, echo contrast with high quality echo. Then 1 – 3 ml absolute alcohol, slowly (1 ml over 3 minutes) with standby pacemaker. Balloon remains inflated for 5 – 10 min after completion of infusion Temporary Pacemaker remains overnight

Non-Surgical Options: ASA Therapy Introduction Non-Surgical Options: ASA Therapy

After 2 ml Pure Alcohol

Systolic Anterior Motion of mitral valve (SAM) Obstructive Hypertrophic Cardiomyopathy Alcohol Septal Ablation (Patient Selection) Obstruction: LV - Ao ≥ 60 mm Hg at rest or with provocation (Valsalva’s maneuver, amyl nitrite, isoproterenol) Systolic Anterior Motion of mitral valve (SAM) Septal thickness ≥ 14 mm

Obstructive Hypertrophic Cardiomyopathy Alcohol Septal Ablation (Results) Approximately 1% will have unfavorable septal artery distribution, papillary muscle, RV outflow tract, LV/RV chamber Resting gradient will decrease or disappear during the procedure (it will usually reappear the next day) 10 – 15% will develop complete heart block which is transient in about half. If present after 24 hours, patient needs pacemaker

MRI: LV mass decreases 8% at 6 months Obstructive Hypertrophic Cardiomyopathy Alcohol Septal Ablation (Results) Late heart block (>24 hours) has occurred in 3% of patients, late as 3 days after procedure. Only prediction of heart block is distance from left main to the first septal artery, Immediate relief of symptoms is placebo effect. Symptom relief begins in 2 – 3 months MRI: LV mass decreases 8% at 6 months Improved symptoms at 6 months in 85%

Annual mortality following procedure is Obstructive Hypertrophic Cardiomyopathy Alcohol Septal Ablation (Results) Long term: Recurrent symptoms: frequently due to non obstructive process. If obstruction remains or recurs, additional septal arteries can be treated. ECHO guidance is most important. Patients who fail to improve should undergo operative septal reduction. Annual mortality following procedure is 2 – 3%/yr, half being non cardiac