Footprints of cardiac mechanical activity as expressed in lung Doppler signals.

AIMS To determine the diagnostic information contained in cardiac pulsatile pressure waves as expressed in the Doppler signals recorded over the right lung. METHODS AND RESULTS The pulsatile characteristics of the pulmonary vascular system were studied by means of the novel pulse Doppler technology in 38 control volunteers, 31 patients with atrial fibrillation (AF) and 7 patients with atrial flutter. The Doppler velocity waveforms recorded were interpreted in relation to the cardiac cycle mechanical events that generate them: Ventricular systole (S), diastole (D) and presystolic left atrial contraction (A). It was demonstrated that in all cases of AF, wave-A was absent. With longer diastole a high frequency velocity waves were visible. It is assumed that they represent the atrial mechanical fibrillation. In the patients with atrial flutter, the single A-wave was replaced by a waveform termed F, the frequency of which exactly matched that of the flutter wave on the ECG. The F-wave had both a positive and negative component. CONCLUSION The lung Doppler signals contain distinct signatures typical of arrhythmias such as AF and atrial flutter that can be used for both diagnosis and to gain insight into the nature of the phenomena.