Myocardial viability at the left ventricular lead location and the occurrence of ventricular tachyarrhythmias in cardiac resynchronization therapy
- Resource Type
- Authors
- L. Lezaic; Igor Zupan; Marta Cvijic; D Zizek
- Source
- European Heart Journal. 34:P1132-P1132
- Subject
- Tachycardia
medicine.medical_specialty
medicine.diagnostic_test
business.industry
medicine.medical_treatment
Cardiac resynchronization therapy
Single-photon emission computed tomography
medicine.disease
Myocardial perfusion imaging
QRS complex
Heart failure
Internal medicine
Cardiology
Medicine
Sinus rhythm
medicine.symptom
Cardiology and Cardiovascular Medicine
business
Coronary sinus
- Language
- ISSN
- 1522-9645
0195-668X
Purpose: There is some conflicting data regarding the potential arrhythmic effect of left ventricular (LV) pacing in cardiac resynchronization therapy (CRT). In heart failure (HF) patients scar-related anisotropy and dispersion of refractoriness provide conditions for re-entry ventricular tachyarrhythmias (VTs). The aim of our study was to analyse the association between myocardial viability at the LV lead location and the occurrence of VTs in patients undergoing CRT. Methods: Before CRT defibrillator device implantation 57 patients with advanced HF [age 62.3±10.2; NYHA II-IV; 38 men (66%); 24 ischaemic aetiology (42%); 48 sinus rhythm (84.2%); QRS duration 165±24 ms] were evaluated using single-photon emission computed tomography (SPECT) myocardial perfusion imaging (20-segment model). LV lead position was determined at implant venography using 2 projections (LAO 30° and RAO 30°) of coronary sinus tributaries. Myocardial viability was calculated as the mean tracer activity in the corresponding segments at left ventricular (LV) lead location. Results: In median follow-up 30 (24-34) months, VTs were registered in 18 patients (31.6%). Patients without VTs had higher myocardial viability at the LV lead position (66.1±10.3% vs. 54.8±11.4% of tracer activity; P = 0.001) than those with VTs. In addition, among patients with registered VTs the extent of regional viability was also related to the number of malignant tachyarrhythmias. In multivariante logistic regression model LV lead viability (OR = 0.90; 95% CI 0.85-0.97; P = 0.003) was the only independent predictor of VT occurrence. After receiver-operating curve analysis cut-off value of 59.63% of mean tracer activity had a sensitivity of 72% and a specificity of 77% for predicting VTs. Conclusion: Myocardial viability at the LV lead position is independently related to the occurrence of VTs in CRT patients. Segments with decreased viability in the potential LV pacing site should be identified before implantation to avoid possible enhancement of electrical instability.