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Persistent atrial standstill
Insights
This case study details permanent atrial standstill in Chagas' Heart Disease, a rare arrhythmia causing syncope. Pacemaker implantation resolved symptoms despite persistent atrial electrical silence.
Area of Science:
- Cardiology
- Electrophysiology
- Chagas Disease Research
Background:
- Chagas' Heart Disease (CHD) can manifest with complex cardiac arrhythmias.
- Atrial standstill, a rare condition characterized by absent atrial electrical activity, poses diagnostic challenges.
Observation:
- A patient with chronic CHD presented with syncopal attacks attributed to a severe dysrhythmia.
- Diagnostic evaluations included electrocardiography, His Bundle electrograms, and hemodynamic assessments.
- Absence of atrial activity and advanced conduction defects were noted, suggesting diffuse atrial involvement.
Findings:
- His Bundle electrogram confirmed absent atrial activity and an advanced conduction defect distal to the bundle of His.
- Atropine administration revealed an accelerated atrioventricular junctional rhythm with a right bundle branch block.
- Epicardial ventricular pacemaker implantation successfully eliminated syncopal episodes.
Implications:
- This case highlights permanent atrial standstill as a treatable cause of syncope in Chagas' Heart Disease.
- Ventricular pacing can effectively manage symptoms even with persistent electrical and mechanical atrial standstill.
- Understanding rare arrhythmias in CHD is crucial for effective patient management and improved outcomes.
Abstract:
The authors present a case of permanent atrial standstill with syncopal attacks, in a patient with chronic Chagas' Heart Disease. The recognition of this dysrhythmia was based upon the conventional and intracavity electrocardiographic tracings in addition to phonomecanographic and hemodynamic data. The recording of the His Bundle electrogram demonstrated the absence of atrial activity, with the His potential preceding all ventricular complexes and an advanced conduction defect distal to the bundle of His. A diffuse type of atrial involvement was suggested by the lack of response to pacemaker stimulation. An increase in ventricular rate following intravenous atropine administration, led to the diagnosis of an a-v junctional rhythm with a widened QRS complex due to an associated right bundle branch block. Following the implantation of an epicardial ventricular pacemaker, the patient became completely asymptomatic despite the persistence of electrical and mechanical atrial standstill.