Effects of Different Pacing Modes on Left Ventricular Relaxation in Closed-Chest Dogs
| العنوان: | Effects of Different Pacing Modes on Left Ventricular Relaxation in Closed-Chest Dogs |
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| المؤلفون: | Shoei K. Stephen Huang, Sheldon E. Litwin, Grace D. Gorman |
| المصدر: | Pacing and Clinical Electrophysiology. 12:1070-1076 |
| بيانات النشر: | Wiley, 1989. |
| سنة النشر: | 1989 |
| مصطلحات موضوعية: | Male, medicine.medical_specialty, Cardiac output, Heart block, Heart Ventricles, Dogs, Internal medicine, Ventricular relaxation, Heart rate, medicine, Animals, cardiovascular diseases, Relaxation (psychology), business.industry, Cardiac Pacing, Artificial, Stroke Volume, Depolarization, General Medicine, Stroke volume, medicine.disease, Disease Models, Animal, Heart Block, Evaluation Studies as Topic, Radiofrequency catheter ablation, Anesthesia, cardiovascular system, Cardiology, Female, Cardiology and Cardiovascular Medicine, business |
| الوصف: | Ventricular relaxation is an important determinant of ventricular filling; impaired relaxation may decrease cardiac output and stroke volume. Relaxation has been shown to occur more quickly following beats with an increased extent of systolic fiber shortening. Since cardiac output and stroke volume are greater during atrioventricular (AV) sequential pacing than during ventricular pacing at identical heart rates, we reasoned that AV sequential pacing would improve relaxation. To assess this hypothesis we studied 11 dogs with chronic (1-3 months) complete heart block (CHB) induced by radiofrequency catheter ablation of the His bundle. Right and left heart pressures, thermodilution cardiac output, and single plane ventriculography were recorded during baseline rhythm (CHB), and VVI, and AV sequential pacing at a heart rate greater than the sinus rate. None had ventriculoatrial conduction. During AV sequential pacing, the AV interval was set at 150 msec. Cardiac output and stroke volume were significantly increased in the AV sequential compared to the VVI pacing mode. Left ventricular pressures, maximal positive and negative dP/dt, and the time constant (T) of isovolumic pressure decay were not different in the two modes. We conclude that despite increased stroke volume in the AV sequential pacing mode, relaxation is unchanged. We believe the lack of change in relaxation is due to nonuniform ventricular activation when depolarization is initiated at the right ventricular apex. |
| تدمد: | 1540-8159 0147-8389 |
| DOI: | 10.1111/j.1540-8159.1989.tb01928.x |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7d0858bc3197d65883a5accea210a754 https://doi.org/10.1111/j.1540-8159.1989.tb01928.x |
| Rights: | CLOSED |
| رقم الانضمام: | edsair.doi.dedup.....7d0858bc3197d65883a5accea210a754 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15408159 01478389 |
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| DOI: | 10.1111/j.1540-8159.1989.tb01928.x |