Peripheral Edema Masks the Diagnoses of P Pulmonale, P Mitrale, and Biatrial Abnormality: Clinical Implications for Patients With Heart Failure

Electrocardiographic changes resulting from pericardial effusion drainage

Electrocardiographic (ECG) changes resulting from drainage of pericardial effusion (PE) have not been systematically studied. In addition, because PE and peripheral edema produce voltage attenuation of the electrocardiogram, we aimed at exploring whether these 2 conditions could be differentiated by electrocardiogram. We previously showed that peripheral edema attenuates amplitudes of QRS complexes and P waves and published a case report showing that attenuation in PE involves QRS complexes but not P waves. Clinical, laboratory, and echocardiographic data and quantitative measurements of amplitudes of QRS complexes and P waves before and after pericardiocentesis in 43 patients were obtained. Although changes of QRS complexes before and after pericardiocentesis were statistically significant, they were not so for P waves. Other ECG measurements before and after pericardiocentesis did not show statistically significant changes, except for heart rate, which decreased, and PR interval and QRS duration, which increased after the procedure. In conclusion, pericardiocentesis results in augmentation of QRS complexes on electrocardiogram, whereas it does not affect amplitude of P waves; this differential from peripheral edema is attributed to the fact that PE around the atria is much less than around the ventricles, and thus alleviation of PE alters the voltage transfer dynamics to the body surface for the atria much less than it does for the ventricles.

Manual-based versus automation-based measurements of the amplitude of QRS complexes and T waves in patients with changing edematous states: clinical implications

Most of the previous work pertaining to the impact of peripheral edema on the ECG has been based on manual measurements. Comparison of manual- and automation-based measurements of P waves has been previously carried out. The objective of this study was to compare manual and automated measurements of QRS complexes and T waves. The sum of the amplitude of QRS complexes for manual (SigmaQRSm) and automated (SigmaQRSa) and for T waves for manual (SigmaTm) and automated (SigmaTa) measured in the 12-leads of the ECGs was calculated in 28 patients with peripheral edema and 28 controls, without change in their weight during hospitalization; data points (n = 125) from all phases of the study were lamped together. SigmaQRSm was 114.1 +/- 46.2, and SigmaQRSa was 125.4 +/- 49.5 (n = 125); correlation of SigmaQRSm and SigmaQRSa was excellent (r = 0.98, P = .00005). SigmaTm was 18.1 +/- 13.3, and SigmaTa was 19.8 +/- 12.7 (n = 125); correlation of SigmaTm and SigmaTa was excellent (r = 0.96, P = .00005). Correlations of SigmaQRSm and SigmaTm (r = 0.43, P = .0002), as well as SigmaQRSa and SigmaTa (r = 0.49, P = .00005) were fair to moderately good, correspondingly. Manual and automated measurements of the sums of the amplitudes of the QRS complexes and T waves are well correlated and differ by approximately 9%, with the manual measurements generating lower values. Automated measurements of the QRS complexes and T waves are reliable and can be used in the diagnosis and monitoring of patients showing changes in the amplitude of these 2 components of the ECG curve.

P-wave and QRS complex measurements in patients undergoing hemodialysis

Hemodialysis (HD) has been associated with an increase in the amplitude of QRS complexes. Experience in a single patient with multiple measurements has shown that HD leads also to augmentation of P-wave amplitude. The objective of this investigation was to evaluate electrocardiogram (ECG) changes with HD in a cohort of patients undergoing this procedure with particular emphasis on the P-wave and QRS complex changes. The sum of amplitudes of P waves (OP) and QRS complexes (OQRS) in millimeters in the 12 leads of the ECG, along with a host of other ECG parameters, body weight, blood pressure, heart rate, electrolytes, and hemoglobin/hematocrit were measured before and immediately after HD in 47 patients. Hemodialysis resulted in a loss of a mean of 3 kg of weight and an increase in the SigmaP, SigmaQRS, mean QRS duration, maximum P-wave duration, and P-wave duration measured in lead II, whereas the changes in mean P-wave and corrected QT interval durations were not statistically significant. Percentage change (Delta%) in SigmaP and SigmaQRS correlated poorly with Delta% in electrolytes, hematocrit, blood pressure, heart rate, and weight. Values for SigmaP and SigmaQRS vs weight were r = 0.105, P = .48 and r = 0.09, P = .51, respectively. The Delta% in SigmaP correlated well with Delta% in SigmaQRS (r = 0.42, P = .003). Alterations in P-wave amplitudes and duration commensurate with the ones affecting the corresponding QRS complexes occur in patients undergoing HD and indicate that evaluation of measurements in serial ECGs should take this into account. The mechanisms of these phenomena continue to be elusive, and whether they represent cardiac and/or extracardiac influences has not as yet been unraveled.

ECG Changes in Response to Diuresis in an Ambulatory Patient With Congestive Heart Failure

This case report describes an ambulatory patient with congestive heart failure and peripheral edema who lost 18 lb in response to enhanced diuresis over the course of 1 week. The ECG showed increases in the amplitude of P waves, QRS complexes, and T waves; the duration of P waves, QRS complexes, and QT intervals; and the dispersion of P and QT. The clinical implications of these ECG changes are discussed.