Limitations of cough in maintaining blood flow during asystole: assessment by two-dimensional and Doppler echocardiography.
It has been previously demonstrated that patients can maintain consciousness by vigorously coughing during episodes of prolonged ventricular asystole or ventricular fibrillation. Using two-dimensional Doppler echocardiography and arterial blood pressure recordings, we evaluated the changes that occur during coughing in nine patients who were dependent on pacemakers and in whom periods of asystole could be induced. During asystole in each patient the mitral valve stayed partially open and the left ventricular area comprised 87% and 90% (apical four-chamber view, short-axis view, respectively) of the area during diastole of paced rhythm. Peak arterial pressure during coughing and asystole was 80% of peak systolic pressure of paced rhythm (P = 0.001). Left ventricular area during coughing was 110% (both apical four-chamber view and short-axis views) of the area during asystole when patients were not coughing. Both the mitral and aortic valves showed no appreciable motion during coughing. During coughing the mean flow velocity across the mitral valve was 0.06 +/- 0.03 m/sec and the flow velocity integral was 0.03 +/- 0.02 cm. Thus coughing during asystole produced minimal flow despite a rise in brachial arterial pressure.
Cohen
A
A
Veterans Administration Medical Center, Washington, DC.
Gottdiener
J
J
Wish
M
M
Fletcher
R
R
D000368:Aged; D001021:Aortic Valve / Q000503:physiopathology; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D003371:Cough / Q000503:physiopathology*; D015150:Echocardiography, Doppler; D006323:Heart Arrest / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008875:Middle Aged; D008943:Mitral Valve / Q000503:physiopathology; D010138:Pacemaker, Artificial