Effect of Diuresis on P-Wave Duration and Dispersion
Effect of Diuresis on P-Wave Duration and Dispersion
Study Objective. To evaluate the effects of changing volume status on P-wave duration and dispersion in patients with decompensated heart failure.
Design. Prospective analysis.
Setting. Hospital cardiology unit.
Patients. Twenty-one patients with symptoms of decompensated heart failure who were treated with diuretics on admission.
Intervention. Twelve-lead electrocardiograms were obtained at baseline and after diuresis. Average, minimum, and maximum P-wave duration and P-wave dispersion (minimum minus maximum duration) were determined.
Measurements and Main Results. P-wave duration was measured manually in all 12 leads by using a 0.5-mm-scale precision ruler and magnifying lens. After 40 ± 23 hours of diuresis, 3 ± 1 L of fluid was removed. A significant correlation was found between average P-wave duration and amount of fluid removed (r = -0.59, p=0.015). Also, average and maximum P-wave duration were significantly decreased with diuresis (p=0.001 and 0.022, respectively). No other P-wave variables were significantly affected.
Conclusions. Diuresis may attenuate electrophysiologic changes caused by fluid overload.
Atrial fibrillation is a cardiac arrhythmia that occurs frequently in patients undergoing open-heart surgery, regardless of their underlying structural heart disease. Recent data suggest that certain electrocardiographic variables may predict the risk of developing atrial fibrillation. P-wave duration and P-wave dispersion are prolonged in patients with a history of paroxysmal atrial fibrillation during periods of sinus rhythm. Maximum P-wave duration and P-wave dispersion also are prolonged at a time when patients undergoing open-heart surgery are at highest risk for developing atrial fibrillation. This is interesting since the risk of atrial fibrillation in this patient population is only transient.
Theoretically, if prolonged P-wave duration and P-wave dispersion predict transient risk of atrial fibrillation, then it may be possible to attenuate the risk through normalization of P-wave variables. A previous study in patients with decompensated heart failure found that P-wave duration and atrial pressure decreased with administration of the potent afterload- and preload-reducing agent nitroprusside. To our knowledge, this is the only study to evaluate P-wave variables in patients with heart failure to date and does not identify the sole role of preload reduction on P-wave duration. It also did not evaluate P-wave dispersion. We evaluated the effects of changing volume status on P-wave duration and dispersion in patients with decompensated heart failure.
Study Objective. To evaluate the effects of changing volume status on P-wave duration and dispersion in patients with decompensated heart failure.
Design. Prospective analysis.
Setting. Hospital cardiology unit.
Patients. Twenty-one patients with symptoms of decompensated heart failure who were treated with diuretics on admission.
Intervention. Twelve-lead electrocardiograms were obtained at baseline and after diuresis. Average, minimum, and maximum P-wave duration and P-wave dispersion (minimum minus maximum duration) were determined.
Measurements and Main Results. P-wave duration was measured manually in all 12 leads by using a 0.5-mm-scale precision ruler and magnifying lens. After 40 ± 23 hours of diuresis, 3 ± 1 L of fluid was removed. A significant correlation was found between average P-wave duration and amount of fluid removed (r = -0.59, p=0.015). Also, average and maximum P-wave duration were significantly decreased with diuresis (p=0.001 and 0.022, respectively). No other P-wave variables were significantly affected.
Conclusions. Diuresis may attenuate electrophysiologic changes caused by fluid overload.
Atrial fibrillation is a cardiac arrhythmia that occurs frequently in patients undergoing open-heart surgery, regardless of their underlying structural heart disease. Recent data suggest that certain electrocardiographic variables may predict the risk of developing atrial fibrillation. P-wave duration and P-wave dispersion are prolonged in patients with a history of paroxysmal atrial fibrillation during periods of sinus rhythm. Maximum P-wave duration and P-wave dispersion also are prolonged at a time when patients undergoing open-heart surgery are at highest risk for developing atrial fibrillation. This is interesting since the risk of atrial fibrillation in this patient population is only transient.
Theoretically, if prolonged P-wave duration and P-wave dispersion predict transient risk of atrial fibrillation, then it may be possible to attenuate the risk through normalization of P-wave variables. A previous study in patients with decompensated heart failure found that P-wave duration and atrial pressure decreased with administration of the potent afterload- and preload-reducing agent nitroprusside. To our knowledge, this is the only study to evaluate P-wave variables in patients with heart failure to date and does not identify the sole role of preload reduction on P-wave duration. It also did not evaluate P-wave dispersion. We evaluated the effects of changing volume status on P-wave duration and dispersion in patients with decompensated heart failure.
Source...