Implantable cardioverter-defibrillator implantation in a patient with atrial standstill

Abstract

We report a 55-year-old female patient who presented with no P waves but with a wide QRS complex escape rhythm at 44 beats/min and prolonged QTc of 0.55 seconds on ECG. The patient had recurrence of ventricular fibrillations and loss of consciousness, and underwent defibrillation and cardiopulmonary resuscitation (CPR) several times because of cardiac arrest. The transthoracic echocardiography showed dilated cardiomyopathy and enlargement of both atria. The Doppler echocardiography documented the absence of A wave in the tricuspid and mitral valve flow. An electrophysiologic study demonstrated electrical inactivity in the right and left atria. Atrial pacing with maximum output did not capture the atria. These findings together with her electrocardiographic finding indicated atrial standstill. Sudden cardiac death was her first clinical manifestation of ventricular arrhythmia. The patient remained asymptomatic after receiving a single chamber implantable cardioverter-defibrillator (ICD) with VVI pacemaker function.

Keywords: Atrial standstill; cardiopulmonary resuscitation; dilated cardiomyopathy; sudden cardiac death.

Fig. 1

Twelve-lead ECG and intracardiac electrogram. (A) Twelve-lead ECG on the 1st day of admission showed an escape distal rhythm at 44 beats/min with wide QRS complex, of 0.12 sec. No P wave was found in ECG. QTc interval was prolonged to 0.55 sec. (B) Recording obtained during EPS after implantation of ICD with VVI pacemaker function. There was no electrical activity on atrial and CS electrograms. ECG, electrocardiogram; ICD, implantable cardioverter-defibrillator; HRA, high right atrium, CS, coronary sinus.

Fig. 2

(A) Chest PA of a single chamber ICD with VVI pacemaker function implanted to the patient. (B) DFT test showed induction of VF, and safe and successful defibrillation at 14.8 J. PA, postero-anterior; ICD, implantable cardioverter-defibrillator; DFT, defibrillation threshold test; VF, ventricular fibrillation.