Structural Heart Disease > Cases
Advanced Hypertrophic Obstructive Cardiomyopathy Treated by Percutaneous Alcohol Septal Ablation (II)
|- Operator : Cheol Whan Lee, MD, PhD / Seong-Wook Park, MD, PhD, Korea|
|A 38-year-old man was admitted to the Asan Medical Center for treatment of advanced hypertrophic obstructive cardiomyopathy. On admission, he had a history of 2 years of chest pain, fainting spells, and palpitation with medical treatment. The patient had a 4/6 ejection murmur at apical area that was aggravated by the Valsalva maneuver, but which diminished when he squatted.|
|The echocardiography showed a hypercontractile left ventricle, a variable pressure gradient across the left-ventricular outflow tract, typical systolic anterior movement of the mitral valves, and mitral incompetence (Figure 1, Figure 2). A peak instantaneous pressure gradient of left ventricular outflow under basal (resting) conditions was 52 mmHg (Figure 3). On the treadmill exercise test, his maximally attained workload was 5 METs and he complained faintness and chest discomfort after stage 2 exercise with Bruce protocol.|
|Left and right heart catheterization was carried out via the right femoral artery under local anaesthesia. Left-ventricular angiography showed a hypercontractile left ventricle and a typical systolic constriction below the aortic valve. There was a 30 mmHg resting intraventricular pressure gradient / measured simultaneously with the trans-septal Brockenbrough catheter and with a 7 F pigtail catheter. The gradient increased to 80 mmHg with postextrasystolic potentiation.|
At first, a temporary pacemaker was placed in the apex of the right ventricle. A 7 F sheath was inserted through right femoral artery and the left coronary was engaged with a 7 F Judkins left catheter. The second major septal branch of the anterior descending coronary artery was identified (Figure 4) and catheterized with a 1.5 x 20mm Ranger balloon (Figure 5). The myocardium perfused by this vessel was enhanced by contrast injections through the balloon catheter with transthoracic echocardiography. After intravenous administration of 3 mg morphine, 2 mL absolute alcohol was slowly injected through the inflated balloon into the vessel and left for 5 min before the balloon was deflated. The patient reported moderate chest discomfort only at the start of the alcohol injection. After the procedure, the left-ventricular angiogram showed no difference in end-diastolic volume but the end-systolic volume was larger and no subaortic obstruction was visible during systole. Final angiography showed no flow in the second septal branch (Figure 6).
The systolic anterior movement of the mitral valve remained visible on echocardiography despite the lack of a significantly accelerated flow. Creatine kinase activity rose to a maximum of 795 IU (with the MB isoenzyme 94.3 IU) within hours of the procedure and fell rapidly thereafter. On the follow up treadmill exercise test, his maximally attained workload increased up to 12 METs. The patient made an uneventful recovery and was discharged 10 days after the intervention. Six months later he had a 1/6 systolic ejection murmur and his chest pain disappeared. Doppler echocardiography showed a decreased outflow-tract gradient (Figure 7) and decreased systolic anterior movement of the mitral valve without mitral incompetence (Figure 8, Figure 9).