B P6 C54 Hypertrophic Cardiomyopathy

Question 1

Predictors of SCD in adult patients with HOCM

Answer 1

1. Massive hypertrophy (wall thickness approaching or exceeding 30 mm)
2. Family history of SCD in first-degree relatives younger than the age of 40 to 50
3. Arrhythmogenic syncope
4. LV systolic dysfunction
5. LV apical aneurysm
6. NSVT (more important for younger patients or when the runs of NSVT are frequent, longer, and/or faster.)
7. Extensive late gadolinium enhancement (LGE) on CMR indicates scarring in the LV wall

Question 2

________________ are the hallmark symptoms attributable to LVOTO

Answer 2

Dyspnea, chest pain/pressure, and/or presyncope that vary from day to day

Question 3

Symptoms are most dramatically promoted by physical effort as________________ drops and contractility is augmented.

Answer 3

Systemic vascular resistance

Question 4

Management of symptoms in HOCM

Answer 4

Optimize volume status (encourage vigorous hydration)
Eliminate or reduce any vasodilator therapies
Empirically start beta blockers, verapamil, or diltiazem because these agents have negative chronotropic effects which help maximize preload by increasing the diastolic filling interval, and negative inotropic effects

Question 5

Performed via an aortotomy, muscle resection is now extended and involves a larger surface area of the septum down to the level of the papillary muscles. Some operators also include plication or other manipulation of the anterior mitral leaflet,

Answer 5

Surgical septal myectomy

Muscle does not “regrow” at the myectomy site; therefore results are durable (recurrent or residual obstruction likely results from inadequate initial resection). In experienced centers, operative (30-day) mortality is less than 1% with a 90% to 95% success rate.

Question 6

Percutaneous procedure during which alcohol is infused into the septal perforator artery that supplies the obstructive hypertrophied septum.

Answer 6

Septal ablation

This results in a scar which causes retraction of the septum as the myocardium remodels post infarct’Patients who respond to ablation have similar symptomatic improvements as patients treated with septal myectomy, and long-term survival is similar.

However, there is a higher need for reintervention following ablation, and higher rate of heart block requiring permanent pacemaker placement

Question 7

Myectomy or alcohol septal ablation is indicated for a peak instantaneous LVOT gradient ____________ at rest or with physiological maneuvers (even if there is no gradient at rest), septal hypertrophy >18 mm, and refractory symptoms despite medical treatment.

Answer 7

> 50 mm Hg

Question 8

Adequate responses to alcohol septal ablation

Answer 8

A reduction of the resting gradient to <30 mmHg and a greater than 50% reduction of the provocable gradient

A biphasic response of the gradient is observed after alcohol septal ablation. An acute response with a striking gradient reduction (probably due to stunning of the myocardium) is followed by a gradient rise to about 50% of the preprocedural level the next day, then a progressive septal remodeling and great reduction of the gradient over 6 to 12 months.