29. Coronary Angiography Hyperdynamic systolic function results in almost complete obliteration of the LV cavity Coronary angiography demonstrate Septal bulge on LV cavity.
Abnormal ECG is seen in only 80% of the patients. Increased voltages c/w left ventricular hypertrophy Repolarization changes Q waves-Widespread deep, broad Q. = not ischemia – reflect anterior septal thickness Many show arrhythmias. Giant negative T waves on ECG.
Parasternal long axis view during diastole (left) and systole (right) ECHO shows hppertrophy(Ant septum>13mm and post septum of free wall > 15mm.) Septum> 1.3 times the thickness of LV free wall. Septum may show “Ground Glass” appearance, due to myocardial fibrosis. SAM of mitral valve, associated with MR. Spade shaped LV cavity.
Decreased projection of basal septum into the LVOT
Gold standard for pts w/ drug-refractory HCM Resect a small portion of myocardium from septum – enlarges LVOT and relieves obstruction; also causes concomitant mitral regurg to disappear Operative mortality: <1% Complications rare (heart block, VSD, aortic regurg)
Alcohol septal ablation. A catheter is inserted into the LAD and directed into the septal branch that supplies blood to the hypertrophied portion of the septum. The septal artery catheter balloon is inflated preventing backwash of alcohol into the remainder of the coronary tree. Through a distal port on the balloon-tipped catheter,1-3 mL of ethanol is injected into the septal artery resulting in a controlled myocardial infarction. This scarring leads to progressive thinning of the septum outflow tract enlargement (mimicking LV remodeling that occurs after myectomy).
Complete heart block: 30-40% in early studies, now <10% using smaller doses of alcohol more selectively Large MIs: from alcohol leakage into other coronary arteries
Non-randomized study – aim to determine outcomes in a tertiary referral center Of 601 patients referred between 1998-2006, 138 chose alcohol septal ablation Median age 64 yo Fewer procedural complications in patients w/ myectomy: combined post-procedural complication rate 26% in ablation vs. 5% in myectomy 2 deaths – 1 patient transferred from OSH w/ cardiogenic shock, 1 patient w/ pulmonary HTN Overall survival: 93.5% at 2 yrs, 88% at 4 yrs
Decreased projection of basal septum into the LVOT
Initial registry study in 2000 looking at the efficacy of ICDs for the prevention of SCD in HCM patients Retrospective multicenter study of 19 centers in US and Italy 128 consecutive patients enrolled; ICDs placed between 1984-1998 85 pts = primary prevention 43 pts = secondary prevention
35% of the primary prevention patients received ICDs based on the presence of only 1 risk factor No significant differences in the likelihood of appropriate discharges among HCM patients with 1,2,or greater than 3 high-risk markers.
Suggests that presence of even 1 risk factor is an indication for ICD in HCM However, need large study looking at the prognostic power of each risk factor over a long period of time
Long-term athletic training can produce “athlete’s heart” = increased LV diastolic cavity dimensions/wall thickness/mass.