The syndrome of inferior non-infarctional Q-waves due to segmental basal left ventricular hypertrophy.

Non-infarctional Q-waves in general are often recorded in the ECG, and are attributed to anatomical and electrical ECG axis shifts, presence of accessory pathways, pregnancy, HCM, and other HCM-like segmental LV myocardial hypertrophic states, that are currently not fully characterized, as to their nosological nature. The present focused review concerns in particular inferior Q-waves and their association with segmental basal anterior and/or septal LV hypertophies due to HCM, and other not yet fully characterized basal segmental LV hypertophies. Insights from the currently available literature on the topic are reviewed, and varying opinions about the nature of such hypertophic states are discussed, with some suggestions, for what is needed to be done, for their further pathlogenetic characterization.

Serial electrocardiograms at follow-up for early detection of transplanted heart rejection: A viewpoint.

This viewpoint proposed that serial electrocardiograms (ECG) could be used to monitor for heart transplantation (HT) rejection, based on the expected attenuation of the amplitude of ECG QRS complexes (attQRS) engendered by the rejection-induced decrease in electrical resistance due to the underlying myocardial edema (ME). Previous work in humans has shown attQRS in the setting of a diverse array of edematous states, affecting the myocardium (i.e, ME) and the body volume conductor "enveloping" the heart. Also, animal and human experience has revealed low electrical resistance during mild/moderate HT rejection. Studies with serial correlations of endomyocardial biopsy (EMB), echocardiography, cardiac magnetic resonance imaging, and ECG are recommended, which will merely require recording of an ECG, when EMB and imaging studies are carried out for monitoring of post-HT rejection.

Comments on "QT interval prolongation in Takotsubo syndrome: a frightening feature with no major prognostic impact".

Dear Editor, Pinho et al. reported on the acquired corrected QT-interval (QTc) prolongation in a retrospective analysis of 113 patients (aged 67.6±11.7, 94.7% female)...

Two Electrocardiographic Aberrations Important for All Caring for Patients to Know about.

Two electrocardiographic (ECG) aberrations encountered daily in ECG interpretation/overreading, which appear to be either unknown or ignored, by all caring for patients, are described herein: the 1st is the transient increase in the amplitude of QRS complexes in the right precordial ECG leads, leading to the erroneous diagnosis of left ventricular hypertrophy, often encountered in patients with episodes of supraventricular tachycardia, rapid sinus tachycardia, and atrial fibrillation; the 2nd is the spurious ST-segment elevations in lateral and/or inferior ECG leads in patients with right bundle branch block, interpreted by the automated ECG diagnostic algorithms as due to "acute myocardial infarction," "ischemic injury," "pericarditis," and "early repolarization," in the absence of such pathologies or electrophysiological explanations.

Towards refining of the proposed ECG-based index of coronary microvascular resistance (ECGMVR).

Assessment of the coronary microcirculation via noninvasive indices of coronary microvascular resistance (MVR), based on coronary angiography (AngioMVR) is currently implemented in patients undergoing coronary angiography, and it is employed by many laboratories. Recently, a proposal has been presented of a new index of MVR, based on the duration of the transient electrocardiogram repolarization and depolarization changes emerging during coronary angiography (ECGMVR). It is paramount that the ECGMVR, which does not require any special expertise, new equipment, additional personnel and costs, or prolongation of the catheterization procedure, undergoes correlation with currently utilized indices of AngioMVR, the TIMI frame count index, and the invasive indices assessing the coronary epicardial and microvasculature states, for its validation. Some additional insights are also included in the present communication for the refinement of ECGMVR implementation.

On the nonpathological nature of ST-segment elevation in lateral leads in patients with CRBBB.

Stable ST-segment elevation (STSE) in the lateral electrocardiogram (ECG) leads (i.e., I, II, aVL, V5, and V6) are frequently encountered in association with stable and transient complete right bundle branch block (CRBBB). These STSE in the lateral ECG leads in patients with CRBBB, represent parallel changes to the ST-segment depression seen in the V1-V3 leads, and both represent secondary ECG changes expected in patients with intraventricular conduction delays, and they are opposite in polarity to the latter part of the QRS complexes. Proprietary automated ECG interpretation algorithms provided by the different electrocardiographs associate such ECG changes in the lateral leads in the presence of CBBB to "lateral myocardial infarction, ischemia, or injury," "pericarditis," or "early repolarization," which results in inappropriate concern among clinicians, and leads to costly unnecessary diagnostic testing. This piece strives to reassure clinicians about the nonpathological nature of lateral STSE in ECGs with CRBBB.

Apparent electrocardiogram left ventricular hypertrophy during tachycardia.

The electrocardiographic transient display of left ventricular hypertrophy (LVH), during rapid heart rates, in the setting of sinus/supraventricular tachycardias and atrial fibrillation, is illustrated via 3 case reports. This common occurrence is expressed by an increase in the S-waves in leads V2-V5, during tachycardias, rendering a false positive diagnosis of LVH by the frequently employed Cornell voltage LVH criteria. This tachycardia-mediated apparent LVH, is unrelated to the occasionally encountered stable, and unrelated to tachycardia, "false positive diagnosis of LVH", which could in reality occasionally reflect altered electrical properties of myocardium that could create a functional substrate for developing arrhythmias. The importance of awareness of this insight by all health professionals is immeasurable, considering that a false positive diagnosis of LVH has major consequences in the management, prognostication, resort to expensive unnecessary testing, and stress to the patients and their families.

A change of heart: Transformation of the electrocardiogram in a patient with apical hypertrophic cardiomyopathy.

An asymptomatic 83-year-old man with a history of hypertension, prior stroke with no residual deficits, and bilateral carotid artery stenosis, presented for evaluation prior to cataract surgery. His transthoracic echocardiogram was typical for apical hypertrophic cardiomyopathy (AHCM), and his electrocardiograms (ECG) showed large precordial R-waves and inverted T-waves, previously associated with AHCM, while his ECG 7 years earlier was normal. Mechanistic explanations for the developed ECG abnormalities, and their importance for the detection and monitoring of patients with AHCM are provided.

A proposal for a reconstruction (derivation) of V1-V6 using leads I, II, and a "sternal notch lead": A solution to the problem of non-reproducibility of precordial leads in serial 12-lead standard electrocardiograms.

Variation of the amplitude and morphology of V1-V6 leads in serial ECGs, due to variation in the placement of V1-V6 recording electrodes, and the noncompliance in placing the V1-V6 electrodes at the recommended thoracic loci, are 2 problems which have defied solution since the advent of electrocardiography. A proposal is presented herein of a set of 3 recorded leads (conventional limb leads I and II, and a lead recorded via an electrode adjacent to the sternal notch [SNL]), aimed at reconstructing the V1-V6 leads, as a function of the 3 recorded leads, employing patient-specific and general (population) coefficients. The SNL electrode is expected to be placed at a designated thoracic site without ambiguity, and thus in conjunction with the limb leads I and II, to yield a hybrid 12-lead ECG with the conventional 6 limb leads and 6 derived V1-V6 leads. The SNL will result in the elimination of the problems of variation in the placement of V1-V6 electrodes, and the noncompliance of placing the V1-V6 electrodes at the recommended thoracic sites, and the resultant variation in the amplitude and morphology of the V1-V6 leads in serial ECGs.

Progression of electrocardiographic changes in a patient with apical hypertrophic cardiomyopathy.

A 58-year-old man asymptomatic from the cardiovascular point of view and with no known relevant family history was found by transthoracic echocardiography to have apical hypertrophic cardiomyopathy (AHCM). His electrocardiogram (ECG) revealed prominent precordial R-waves, particularly in V3-V4 leads, and "giant" (>1.0 mV), inverted T-waves, previously associated with AHCM. ECGs recorded 17 and 13 years previously, did not disclose such abnormalities, as the ones of his current ECG. The presented case illustrates a potential role of serial ECGs (along with serial imaging testing) in detecting the development and progression of regional left ventricular hypertrophy in patients with AHCM, and probably in other hypertrophic cardiomyopathy phenotypes.