Septal ablation

Patients who have not obtained a satisfactory result after surgical myectomy may also be candidates for septal ablation. Selected patients with advanced function class II with obstructive symptoms that interfere with their occupation may also be candidates for intervention. 

Patients with the non-obstructive form of hypetrophic cardiomyopathy should not undergo septal ablation. Patients with congential anomalies of the mitral valve apparatus, associated heart lesions (e.g., advanced multivessel coronary artery disease) requiring surgical correction, unfavorable distribution of septal hypertrophy with mild proximal thickening, basal septal wall thickness < 18 mm, or anatomically unsuitable septal perforators should not be candidates for septal ablation. 

Dobutamine, an inotropic and catecholamine-inducing drug and a powerful stimulant of subaortic gradients in normal hearts and cardiac conditions other than hypertrophic cardiomyopathy, is not recommended to provoke outflow gradients for assessing the appropriateness of septal ablation (I),... 

Following septal ablation, patients should be monitored in a coronary care unit for 24 to 48 hours and the temporary pacing wire should be removed at the end of this period in the absence of atrioventricular block. Patients may then be transferred to a telemetry unit for monitoring of arrhythmias. Total hospitalization is usually for three to five days to monitor for occurrence of complete heart block that would require a permanent pacemaker. A sizeable infarction is induced with alcohol ablation and causes creatinine phosphokinase to peak at 1000 to 1500 one day after the ablation. Patients should be maintained on aspirin indefinitely. 

Successful septal ablation leads to significant improvement in objective tests of exercise performance in terms of treadmill exercise time and peak oxygen consumption in follow-up studies over 3 to 18 months (Table 2) (I 1-15). Significant and sustained improvement in echocardiographic measures of diastolic function are seen up to two years which may account for the improved functional status after septal ablation (16). 

The three-month (II) and one-year (10) results of both surgical myomectomy and alcohol septal ablation were comparable, however, surgical myomectomy was superior to ablation in terms of improved exercise test parameters (Table I) (14). Studies indicate maintenance of clinical and hemodynamic... 

TSable 2 Summary of studies comparing surgical myectomy and septal ablation... 

Note Pre indicates preintervention post indicates postintervention. ap<0.05 versus baseline values. bp<0.05 versus septal ablation. 

TSable 3 Summary of septal ablation follow-up studies... 

Table 4 Reported complication after surgical myectomy or septal ablation...

Septal ablation related mortality at experienced centers is currently 1% to 2%, similar to that of surgical myectomy (Table 4). Conduction system abnormalities are relatively common complications of septal ablation, Permanent right bundle branch block occurs in about 50% of patients and transitory complete heart block in 60% and permanent pacemakers required for high grade atrioventricular block in about 5% to 20%, Concerns of late occurrence of complete heart block following septal ablation mandates in-patient monitoring for 4 to 5 days,... 

Chest pain during septal ablation commonly occurs and is effectively managed by analgesic therapy. Intensive care unit monitoring is employed routinely postprocedure in anticipation of ventricular arrhythmias during the initial period of myocardial injury, Prophylactic antiarrhythmic therapy has not been used in our center,... 

A profound complication of septal ablation is anterior Ml due to ethanol reflux from the septal perforator down the left anterior descending artery. This can be avoided by careful position of the balloon and angiographic monitoring. Other rare complications include coronary dissection, perforation, thrombosis, and spasm. 

Faber L, Seggewiss H, Welge D, et al. Echo-guided percutaneous septal ablation for symptomatic hypertrophic obstructive cardiomyopathy 7 years of experience. Eur J Echocardiogr 2004 5 347-355. 

Jassal DS, Neilan TG, Fifer MA, et al. Sustained improvement in left ventricular diastolic function after alcohol septal ablation for hypertrophic obstructive cardiomyopathy. Eur Heart J 2006. 

Fernandes VL, Nagueh SF Wang W, et al. A prospective follow-up of alcohol septal ablation for symptomatic hypertrophic obstructive cardiomyopathy—the Baylor experience (1996-2002). Clin Cardiol 2005 28 124-130. 

Yoerger DM, Picard MH, Palacios IF et al. Time course of pressure gradient response after first alcohol septal ablation for obstructive hypertrophic cardiomyopathy. Am J Cardiol 2006 97 151 I — 1514. 

Chang SM, Lakkis NM, Franklin J, et al, Predictors of outcome after alcohol septal ablation therapy in patients with hypertrophic obstructive cardiomyopathy, Circulation 2004 109 824-827. 

Talreja DR, Nishimura RA, Edwards WD, et al. Alcohol septal ablation versus surgical septal myectomy comparison of effects on atrioventricular conduction tissue, J Am Coll Cardiol 2004 44 2329-2332. 

I Veselka J, Prochazkova S, Duchonova R et al. Alcohol septal ablation for hypertrophic obstructive cardiomyopathy Lower alcohol dose reduces size of infarction and has comparable hemodynamic and clinical outcome. Catheter Cardiovasc Interv 2004 63 231-235. 

Veselka J, Duchonova R, Prochazkova S, et al. Effects of varying ethanol dosing in percutaneous septal ablation for obstructive hypertrophic cardiomyopathy on early hemodynamic changes. Am J Cardiol 2005 95 675-678. 

Ablation of the myocardium using alcohol is another alternative to surgery. Septal ablation with alcohol results in the same type of outcomes as seen with myectomy. Long-term follow-up is limited because this procedure has been used for less than a decade. Since it is a percutaneous procedure (similar to cardiac catheterizations), it is being done more frequently than myectomy. There is some concern that the risk for arrhythmia-related cardiac events may increase following alcohol ablation. Long-term follow-up is needed to assess this risk. Complete heart block is a common complication of septal... 

B9. Bradham, W. S., Release of matrix metaUoproteinases following alcohol septal ablation in hypertrophic obstructive cardiomyopathy. J. Am. Coll. Cardiol. 40, 2165-2173 (2002). 

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