Identification of acute ST-elevation myocardial infarction via remote implantable loop recorder monitor.

The indications for the use of implantable loop recorders include the evaluation of unexplained palpitations and syncope, embolic stroke of undetermined source, dizziness and lightheadedness presumed to be due to arrhythmogenic etiology, and for atrial fibrillation to guide antiarrhythmic drug therapy or catheter ablation efficacy. Long-term monitoring is especially beneficial if symptoms occur sporadically or are asymptomatic in nature. This is the first case to our knowledge of an acute ST-elevation myocardial infarction which was identified from remote monitoring of an implantable loop recorder through a device clinic.

Cardiac Memory T-wave Inversions Noted with Ventricular Pacing: A Possible Electrocardiographic Marker of Appropriate Conduction System Pacing.

Cardiac memory is a common condition occurring after a period of abnormal depolarization, such as with right ventricular apical pacing. With restoration of normal conduction, the T-wave "remembers" the direction of the QRS vector of the previously aberrantly conducted complexes, creating diffusely inverted T-waves on the electrocardiogram. The presence of diffuse T-wave inversions with this phenomenon may be confused with myocardial ischemia and may continue to be present for several weeks after restoration of normal conduction. Here, an interesting electrocardiogram obtained after pacemaker implantation showing the opposite effect, ie, the finding of memory T-waves occurring during pacing after a period of intrinsic atrioventricular nodal conduction, is presented. In this case, the patient had an underlying left bundle branch block, which subsequently normalized as a result of conduction system pacing. The memory T-waves became evident after pacing was performed, suggesting a potential marker for restoration of the normal ventricular activation sequence with left bundle branch pacing and normalization of the baseline intraventricular conduction defect.

Resynchronization Therapy During Sustained Ventricular Tachycardia.

A 62-year-old gentleman with a history of an ischemic cardiomyopathy and previous implantation of a biventricular cardioverter-defibrillator presented with complaints of palpitations and a wide complex ventricular paced rhythm at 120 bpm. This was originally thought to be ventricular tracking of an atrial tachycardia at the upper tracking rate, as the patient remained hemodynamically stable for three consecutive days in this rhythm. On the third day, the patient's implantable cardioverter-defibrillator (ICD) was interrogated and it was found that he was indeed in a sustained ventricular tachycardia with biventricular pacing being delivered as a function of the ventricular sense response feature. When this feature was turned off, the patient immediately deteriorated hemodynamically and required a commanded shock through the ICD to terminate the tachycardia. This is an extremely rare presentation of this pacing feature found in biventricular ICDs, which in this case provided significant hemodynamic benefit during a malignant arrhythmia.

Management of Atrial Fibrillation Post Bypass Surgery with Intravenous Sotalol: A Case Study.

Intravenous sotalol has been available for many years outside of the United States, but has only recently become available in the US. The safety and feasibility of intravenous sotalol for the prevention of recurrent atrial fibrillation following bypass surgery has not been described. The present case study is of a patient with several other co-morbidities undergoing coronary artery bypass graft surgery, who post-operatively developed atrial fibrillation. The patient received intravenous sotalol and was then transitioned to oral sotalol. The patient remained hemodynamically stable, with normal QTc and without further atrial fibrillation or tachyarrhythmias in the post-operative period until discharge. Intravenous sotalol is a reasonable alternative to intravenous amiodarone in the post bypass surgery patient with better tolerability and safety profile.