title: Non-invasive methods for evaluating the importance of heart rate and atrial activity in cardiac pacing. Results of ballistocardiography and digital plethysmography studies in six patients with heart block.
abstract: Ultralow frequency ballistocardiography (UFB) and digital pulse plethysmography (DPP) were performed in six patients with an external artificial pacemaker system. UFB was used mainly to evaluate the force of contraction of the left ventricle (IJ amplitude) and DPP for evaluating relative changes in the peripheral pulse volume. Four patients were studied at 40, 50, 60, 70, 80, 90 and 100 beats/min. There was a significant decrease (p less than 0.001) in LJ and pulse amplitudes when the heart rate increased from 40 to 100 beats/min. A positive correlation between relative IJ and pulse amplitude was observed in all cases studied. In beat-to-beat analysis it was found that the importance of the PR interval for the IJ and pulse amplitudes varied between patients. It is concluded that both UFB and DPP may be of value in clinical practice for evaluating hemodynamics in patients with slow spontaneous heart rate. The methods may be of help in selecting the most effective type of pacemaker for the individual patient.
mesh_terms: D000368:Aged; D001450:Ballistocardiography; D002304:Cardiac Pacing, Artificial; D005069:Evaluation Studies as Topic; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy*; D006339:Heart Rate; D006801:Humans; D008297:Male; D010991:Plethysmography; D011674:Pulse