Tuberk Toraks 2014;62(4):325-326
Amfizemde elektrokardiyogram: hızlı yatakbaşı tanısal tarama testi
Nauman KHALID1, Lovely CHHABRA1, David H. SPODICK2
1 Connecticut Üniversitesi Tıp Fakültesi, İç Hastalıkları Anabilim Dalı, Hartford Hastanesi, Hartford, CT
1 Department of Internal Medicine, Faculty of Medicine, University of Connecticut, Hartford Hospital, Hartford, CT
2 Massachusetts Üniversitesi Tıp Fakültesi, İç Hastalıkları Anabilim Dalı, Saint Vincent Hastanesi, Worcester, MA
2 Department of Medicine, Faculty of Medicine, University of Massachusetts, Saint Vincent Hospital, Worcester, MA
We read with great pleasure the work by Akturk et al. published in a recent issue of the Tuberk Toraks (1). In their study, the authors have highlighted the importance of vertical P-vector in diagnosing chronic obstructive pulmonary disease (COPD).
Our group previously published a similar study on a larger patient population which demonstrated that a vertical frontal P-vector can serve as a rapid bedside screening tool for screening emphysema in the general unselected hospitalized population (2). We also showed an inverse correlation of the degree of P-vector verticalization with forced expiratory volume (FEV1). In our other studies, we also showed a correlation of the frontal P-vector verticalization with the radiological severity of emphysema (as estimated by radiographic percentage of emphysematous area and visual scoring of emphysema) (3,4). Interestingly, predominant lower lobe emphysema was found to have the most significant correlation with the frontal P-vector verticalization as compared to the other forms of emphysema. Several explanations have been proposed previously to explain the P-wave verticalization in emphysema, however the most plausible is the downward displacement of the right atrium caused by a progressive flattening of the diaphragm, as the right atrium is attached to the diaphragm by a dense pericardial ligament (5). The schematic illustration is provided in the Figure 1.
One must also remember that the P-vector verticalization in emphysema has a direct correlation with some of the other P-wave indices like terminal force in V1 (Ptf), thus caution should be employed while interpreting left atrial enlargement based on the Ptf in such patients (6). This finding could possibly be due to either net cancellation of right atrial potential by overwhelming left atrial forces, or it could be more likely due to positional displacement of the right atrium (6). P-pulmonale is a well known electrocardiographic marker for diagnosing emphysema, however interestingly in contrast to a general clinical perception, this is the least sensitive electrocardiographic marker for diagnosing pulmonary emphysema although it carries a high specificity (6). We commend the authors for reiterating the importance of electrocardiography for diagnosing pulmonary disorders such as emphysema. Given the current evidence, clinicians can use electrocardiography (an inexpensive tool) not only for routine emphysema screening, but also for assessing the disease severity. A quick look at the surface ECG for either an inverted P wave in lead aVL or the P-wave amplitude in lead III > I can serve as a quasi-diagnostic marker for emphysema (7). Clinicians should thus be aware of these valuable electrocardiographic facts for a quick diagnostic emphysema screening and should employ cautionary interpretation of other P-indices like P-tf.
CONFLICT of INTEREST
Dr. David Spodick receives royalties from his textbook, "The Pericardium: A Comprehensive Textbook (Fundamental and Clinical Cardiology), Marcel Dekker, New York 1997".
Yazışma Adresi (Address for Correspondence)
Dr. Nauman KHALID
Connecticut Üniversitesi Tıp Fakültesi,
İç Hastalıkları Anabilim Dalı,
HARTFORD - CT