Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc
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Ann Noninvasive Electrocardiol · Jan 2005
Heart rate variability fraction--a new reportable measure of 24-hour R-R interval variation.
The scatterplot of R-R intervals has several unique features. Its numerical evaluation may produce a new useful index of global heart rate variability (HRV) from Holter recordings. ⋯ We introduced a new index of HRV, which is easy for computation, robust, reproducible, easy to understand, and may overcome the limitations that belong to the standard HRV measures. This index, named HRV fraction, by combining magnitude, distribution, and heart-rate influences, might become a clinically useful index of global HRV.
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Ann Noninvasive Electrocardiol · Jan 2005
Diagnosis of ventricular aneurysm and other severe segmental left ventricular dysfunction consequent to a myocardial infarction in the presence of right bundle branch block: ECG correlates of a positive diagnosis made via echocardiography and/or contrast ventriculography.
A diagnostic ECG sign of a ventricular aneurysm (VA) consequent to a myocardial infarction (MI) in the presence of complete left bundle branch block was recently described, and consists of the presence of ST-segment elevation (+ST), instead of the expected ST-segment depression (-ST), in leads V4-6. Generally, complete right bundle branch block (RBBB) is associated with -ST in ECG leads V1-3. We hypothesized that stable +ST, instead of the expected -ST in leads V1-3 in patients with RBBB could be also diagnostic of a VA and other severe segmental left ventricular dysfunction (VA/SSD). Thus, this study was performed to explore the feasibility of using the ECG to diagnose a VA/SSD in the presence of RBBB, and to evaluate the determinants of such diagnosis. ⋯ VA/SSD can be diagnosed in the presence of RBBB by the concordant to the QRS repolarization changes (+ST) in leads V1-3. Positivity of this ECG marker for VA/SSD correlates with involvement of the septal or anterior myocardial regions, and represents mechanistically a superimposition of primary repolarization alterations, overcoming the secondary such changes.