Background: Hypertrophic obstructive cardiomyopathy (HOCM) is a complex disease with unique pathophysiologic characteristics and a great diversity of morphologic,functional and clinical features. Percutaneous transluminal septal myocardial ablation (PTSMA) using alcohol injection via a catheter into the septal branch of the left anterior descending coronary artery has been recently introduced as a promising nonsurgical therapy for HOCM. However, the relationship between the volume and velocity of intracoronary injection of absolute alcohol and the size of the resultant myocardial infarct has not been investigated. We therefore studied such a relationship in piglets.
Objectives: To investigate the relationship between the volume and velocity of selective intracoronary alcohol injection by means of a catheter and the size of the resultant myocardial infarction.
Methods: Twenty piglets were equally divided at random into four groups (n=5 in each) according to the volume and the velocity of intracoronary absolute alcohol injection and the coronary arteries injected. Group I: the volume and velocity of injection of alcohol into the left circumflex coronary artery (LCX) were 0.5 ml and 0.2 ml/s, respectively. Group II: the volume and velocity of injection into LCX were 2.0 ml and 0.2 ml/s, respectively. Group III: the volume and velocity of injection of alcohol into the left anterior descending coronary artery (LAD) were 1.2 ml and 0.06 ml/s, respectively. Group IV: the volume and velocity of injection into the LAD were 1.2 ml and 1.2 ml/s, respectively. The resultant myocardial infarcts were then quantitatively measured 6 h after myocardial ablation.
Results: The myocardial infarct size for group I was 4.26+/-2.71(%), for group II was 10.12+/-4.55(%), for group III was 5.84+/-1.21(%) and for group IV was 7.11+/-1.63(%). There were significant differences in myocardial infarct size with different volumes of intracoronary absolute alcohol injection (0.02<P<0.05). but there were no apparent differences found in myocardial infarct size with different velocities of intracoronary alcohol injection (0.05<P<0.2).
Conclusions: The myocardial infarct size is directly related to the volume of intracoronary absolute alcohol injection during myocardial ablation by a catheter, but has no relation to the injection velocity.