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Atrial contribution to ventricular ejection in sequentially paced patients
J Kvasnicka1, M Tauchman, D Kovár
1First Medical Department, Faculty Hospital, Faculty of Medicine, Charles University, Hradec Králové, Czech Republic.
Insights
This study introduces a new method to measure the atrial contribution to ventricular ejection in paced patients. This atrial contribution is dependent on the atrioventricular interval and is reproducible.
Area of Science:
- Cardiology
- Physiology
Background:
- The atrial contribution to ventricular ejection is crucial for cardiac function.
- Assessing this contribution in sequentially paced patients requires reliable quantitative methods.
Purpose of the Study:
- To describe a novel method for the quantitative assessment of the atrial contribution to ventricular ejection.
- To evaluate the atrioventricular interval dependency and reproducibility of this measurement.
Main Methods:
- A new method was developed to measure the atrial contribution (AC).
- AC was defined as the pulse pressure decrement (invasive arterial measurement) induced by temporarily switching off the atrial pacing impulse.
- Measurements were performed in 17 sequentially paced patients.
Main Results:
- The atrial contribution (AC) was found to be dependent on the atrioventricular (AV) interval.
- The method demonstrated good reproducibility (mean difference between measurements: 9.3%, S.D. 8.4%).
- At a 170 ms AV interval, AC varied significantly: 29.3% in sick sinus syndrome, 27.0% in complete AV block, and 10.8% in complete AV block with heart dysfunction.
Conclusions:
- A novel, reproducible method for quantifying the atrial contribution to ventricular ejection in sequentially paced patients has been established.
- The atrial contribution is significantly influenced by the atrioventricular interval.
- This method can differentiate cardiac function in patients with varying degrees of conduction abnormalities.
Abstract:
A new method for quantitative assessment of the atrial contribution to ventricular ejection in sequentially paced patients is described. The atrial contribution (AC) has been defined as the pulse pressure decrement (invasive arterial measurement by a canulla inserted into the brachial artery), expressed in percent of the control pulse pressure, induced by switching off the atrium activating impulse for one beat. In 17 patients, the AC was found to be atrioventricular (AV) interval dependent, the measurements were well reproducible (the mean difference between two measurements at different times was 93%, S.D. 8.4). For the AV interval of 170 ms, it was found to be 293% (+8.9) in patients with the sick sinus syndrome, 27.0% (+3.2) in patients with complete AV block and only 10.8% (+2.1) in a patient with complete AV block and heart dysfunction.