A wide QRS tachycardia in a left univentricular pacing system: what is the mechanism?
| Autor: | Pierre Mondoly, Aurélien Hébrard, Jean-Thomas Aubert, Alexandre Duparc |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Bradycardia
Male medicine.medical_specialty Pacemaker Artificial Defibrillation medicine.medical_treatment Heart Ventricles Bundle-Branch Block Ventricular tachycardia Electrocardiography Heart Conduction System Physiology (medical) Internal medicine medicine Humans Coronary Vein Ejection fraction Ischemic cardiomyopathy Left bundle branch block business.industry Equipment Design Middle Aged medicine.disease Ventricular fibrillation cardiovascular system Cardiology medicine.symptom Cardiology and Cardiovascular Medicine business Follow-Up Studies |
| Zdroj: | Heart rhythm. 8(7) |
| ISSN: | 1556-3871 |
| Popis: | Case summary A 55-year-old man was referred to our institution for cardiac resynchronization therapy-defibrillator (CRT-D) implantation. He had suffered severe ischemic cardiomyopathy with low left ventricular (LV) ejection fraction of 20%, left bundle branch block, and New York Heart Association (NYHA) Class III symptoms despite optimal medical treatment. Magnetic resonance imaging showed a large anterior and lateral scar, with preserved tissue in the septal and posterior regions. In April 2009 he underwent CRT-D implantation with a Boston Scientific COGNIS P107 (SaintPaul, Minnesota, USA). The right ventricular (RV) lead (Guidant Endotak Reliance 0185 Saint-Paul, Minnesota, USA) was screwed into the RV apex; the right atrial (RA) lead (Medtronic Capsurefix 5076, Minneapolis, Minnesota, USA) was screwed into the RA appendage; and the LV lead (Medtronic Attain 4194) was positioned in a posterolateral coronary vein (Figure 1). All leads showed normal electrical values: pacing thresholds were 0.7, 0.7, and 0.8 V at 0.4 ms for the RA, RV, and LV leads, respectively; impedances were 597, 636, and 643 , respectively; and signal amplitudes were 5, 11.5, and 4.6 mV, respectively. Defibrillation testing was performed, and a 31-J first shock successfully cardioverted the induced ventricular fibrillation. Bradycardia pacing parameters were mode DDD, lower rate limit 50 bpm, and maximum tracking rate (MTR) 130 bpm. Figure 2 shows 12-lead ECGs recorded during atrioventricular (AV) optimization. It appeared that LV-only pacing mode with paced AV delay of 140 ms and sensed AV delay of 80 ms was the most effective mode for obtaining the |
| Databáze: | OpenAIRE |
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