Alcohol

5 WARNINGS AND PRECAUTIONS • Transient heart block: Transient heart block is common at the time of injection. A temporary pacing wire is routinely inserted to mitigate transient heart block. (5.1) • Persistent heart block: Approximately 10% of complete heart block events become permanent and require placement of a permanent pacemaker. (5.1) • Remove the temporary pacemaker lead if no episode of high-degree atrioventricular block occurs. (5.1) • Monitor the patient for heart failure, chest pain, and arrhythmias several days after the procedure. (5.1, 5.2, 5.3) 5.1 Heart Block Transient Heart Block Transient heart block is common at the time of dehydrated alcohol, such as dehydrated alcohol injection, injection into a septal artery. Prior to the injection, a temporary pacing wire is routinely inserted into the apex of the right ventricle, usually via the femoral vein, to treat transient heart block. The pacing lead can be removed if no episode of high-degree atrioventricular block occurs, usually after several hours of observation following percutaneous transluminal septal myocardial ablation. Persistent Heart Block Approximately 10% of complete heart block events become permanent and require placement of a permanent pacemaker following percutaneous transluminal septal myocardial ablation. Risk factors for permanent pacemaker dependency after septal ablation include a baseline PQ interval >160 ms, baseline minimum heart rate < 50 bpm, baseline left ventricular outflow gradient >70 mmHg, maximum QRS during the first 48 hours > 155 ms, 3rd degree atrio-ventricular block occurring during the procedure, and no clinical recovery between 12 to 48 hours after the procedure. 5.2 Myocardial Infarction Injection of dehydrated alcohol is intended to create a controlled myocardial infarction for therapeutic purposes. However, excessive myocardial necrosis and subsequent heart failure have been reported. Factors increasing the risk of excessive tissue necrosis include higher volume of alcohol used and a higher number of septal branches injected to reduce the left ventricular outflow tract gradient. 5.3 Ventricular Arrhythmia Ventricular tachycardia and ventricular fibrillation requiring electrocardioversion occurred at a frequency of approximately 1%. Perform continuous electrocardiographic monitoring for 48 hours after the procedure.