Interventional Therapy (continuance)

Percutaneous Transmyocardial Septal Ablation (PTSMA) in Hypertrophic-Obstructive Cardiomyopathy

In hypertrophic-obstructive cardiomyopathy, most patients do not become asymptomatic from drug therapy alone. Thus, PTSMA offers a good option to eliminate or to reduce intraventricular obstruction and to improve exercise tolerance and overall symptoms. If an adequate septal coronary side-branch exists, which it does in 90% of individuals, it will be probed with a coronary wire. Over that wire, a special balloon is introduced into the first septal side-branch. By balloon inflation, the septal side branch is closed off towards the left anterior descending coronary artery. Echocardiographic contrast agent is then administered via the lumen of the balloon into the distal side-branch. Transthoracic echocardiography demonstrates that only the culprit myocardial region is contrast enhanced. Provided that is the case, 2 ml of a 95% alcoholic solution are subsequently injected. This causes an intraseptal myocardial infarction with complete loss of function and subsequent scarring, lowering the degree of obstruction. In many patients (>50%), obstruction disappears completely. Either immediately or during the first days after the procedure, atrioventricular block is observed in about 30 to 40% of patients. For this reason, an external pacemaker connected to a prophylactically placed right ventricular electrode is mandatory. In most cases, atrioventricular block regresses within 4 days. Only in 5% of all ablation patients, permanent pacemaker implantation is required. The procedure is followed by 3 days of monitoring in the intensive care unit and another 4 days in a regular ward, where the patient is mobilized and stays attached to a bed-side monitor at night.

		Echocardiographic guidance in PTSMA: After intracoronary injection of contrast agent, the target area responsible for obstruction is contrast enhanced prior to alcohol administration. LA, left atrium; LV, left ventricle.