Summary

Background: Percutaneous transluminal septal ablation was recently introduced as an alternative to surgical treatment of hypertrophic obstructive cardiomyopathy. In this procedure, alcohol is injected into a proximal septal artery to create a localized myocardial infarction.

Objectives: To characterize the immediate and mediumterm results following PTSMA.

Methods: Of 13 patients referred for PTSMA, 8 were found suitable for the procedure. Hemodynamic parameters were evaluated prior to and following the procedure, and clinical and echo-Doppler parameters at 2 weeks and 9 months later.

Results: The procedure was technically successful in all patients. Resting left ventricular outflow gradient at rest (by Doppler) fell from 82 + 37 to 15 + 8 mmHg (P<0.001) 9 months later. Late post-procedural gradient after the Valsalva maneuver was 2 + 24 mmHg. The degree of mitral regurgitation fell from 2.0 + 0 to 1.5 + 0.5 (P<0.05). New York Heart Association class for dyspnea improved from 2.8 + 0.5 to 1.8 + (P<0.01) and Canadian Cardiovascular Society class for angina from 2.0 + 1.3 to 1.3 + 1.2 (P=0.08). Complete right bundle branch block developed in six patients, temporary complete atrioventricular block in three, and persistent block requiring permanent pacing in one. No flow in the distal left anterior descending coronary artery (presumably due to spilling of alcohol) was seen in one (with development of a small antero-apical infraction) and ventricular fibrillation 2 hours post-procedure in one. None of the patients died.

Conclusion: PTSMA provided a substantial reduction in left ventricular outflow gradient associated with an improvement in symptomatology. Serious complications are not uncommon. Long-term follow-up is unknown.