Rodrigo Daminello-Raimundo

Main artifacts in electrocardiography

Electrocardiographic artifacts are defined as electrocardiographic alterations, not related to cardiac electrical activity. As a result of artifacts, the components of the electrocardiogram (ECG) such as the baseline and waves can be distorted. Motion artifacts are due to shaking with rhythmic movement. Examples of motion artifacts include tremors with no evident cause, Parkinson’s disease, cerebellar or intention tremor, anxiety, hyperthyroidism, multiple sclerosis, and drugs such as amphetamines, xanthines, lithium, benzodiazepines, or shivering (due to hypothermia, fever (rigor due to shaking), cardiopulmonary resuscitation by chest compression (oscillations of great amplitude) and patients who move their limbs during the test, causing sudden irregularities in the ECG baseline that may resemble premature contractions or interfere with ECG wave shapes, or other supraventricular and ventricular arrhythmias. When the skeletal muscles experience shaking, the ECG is “bombarded” by apparently random electrical activity.

Transient left septal and anterior fascicular block associated with type 1 electrocardiographic Brugada pattern

The left septal fascicular block (LSFB) or blockage of the middle fibers of the left bundle branch is probably caused mainly by - in the developed world - the proximal obstruction of the left anterior descending artery (LAD) before its first anterior septal perforator branch (S1). The association of transient LSFB and left anterior fascicular block (LAFB) - left bifascicular block - and the electrocardiographic type 1 Brugada pattern (BrP) has not been described in the literature yet.

Unusual ST-Segment Elevation in the Anterolateral Precordial Leads: Ischemia, Brugada Phenocopy, Brugada Syndrome, All, or None?

The patient is a 65-year-old white male with history of type 2 diabetes mellitus, hypertension, chronic smoking, and prior stroke with residual left hemiparesis and aphasia. His medication included losartan, furosemide, simvastatin, and metformin.nnHe was admitted to the emergency room in cardiac arrest and was quickly resuscitated with cardiopulmonary resuscitation and external electric cardioversion maneuvers. Immediately after return of spontaneous circulation, a 12-lead ECG was performed (Figure 1).nnnnFigure 1. nECG performed immediately after cardiopulmonary arrest reversion. nnnnBased on the ECG, what is the most likely etiology of his cardiac arrest?nnPlease turn the page to read the diagnosis.nnThe firstECG shows accelerated junctional rhythm and a heart rate of 94 bpm, with J point and anterior …

Transient left septal fascicular block in the setting of acute coronary syndrome associated with giant slurring variant J-wave

We report a case of acute coronary syndrome with transient prominent anterior QRS forces (PAF) caused by proximal subocclusion of the left anterior descending (LAD) coronary artery before the first septal perforator branch. The ECG change indicates left septal fascicular block (LSFB) with associated slurring‐type giant J‐wave. Currently, this J‐wave variant is considered as a lambda‐like wave or QRS‐ST‐T “triangulation”. Its presence is indicative of poor prognosis because of the risk for cardiac arrest as a consequence of ventricular tachycardia/ventricular fibrillation (VT/VF).

Transient left anterior and septal fascicular blocks after self-expandable percutaneous transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is indicated in severe symptomatic aortic stenosis, when there is intermediate‐high surgical risk, or a condition considered inoperable, as in the case of “porcelain aorta” that could turn clamping or cannulation of the ascending aorta hazardous in open‐heart surgery. Among the complications of this less invasive procedure, intraventricular conduction disorders subsequent to the procedure stand out. TAVI causes worsening of intraventricular dromotropic disorders in more than 75% of the cases, with the presence of preexisting right bundle branch block and first‐degree atrioventricular block, deep prosthesis implant, male gender, size of the aortic annulus smaller than the prosthesis, and porcelain aorta being predictive of requirement for permanent pacemaker implant.

Catecholaminergic polymorphic ventricular tachycardia, an update

Catecholaminergic polymorphic ventricular tachycardia is a rare devastating lethal inherited disorder or sporadic cardiac ion channelopathy characterized by unexplained syncopal episodes, and/or sudden cardiac death (SCD), aborted SCD (ASCD), or sudden cardiac arrest (SCA) observed in children, adolescents, and young adults without structural heart disease, consequence of adrenergically mediated arrhythmias: exercise‐induced, by acute emotional stress, atrial pacing, or β‐stimulant infusion, even when the electrocardiogram is normal. The entity is difficult to diagnose in the emergency department, given the range of presentations; thus, a familiarity with and high index of suspicion for this pathology are crucial. Furthermore, recognition of the characteristic findings and knowledge of the management of symptomatic patients are necessary, given the risk of arrhythmia recurrence and SCA. In this review, we will discuss the concept, epidemiology, genetic background, genetic subtypes, clinical presentation, electrocardiographic features, diagnosis criteria, differential diagnosis, and management.

Transient prominent anterior QRS forces in the setting ST segment elevation coronary syndrome: Left septal fascicular block

Numerous successive publications have shown that transient prominent anterior QRS forces (PAF) in the setting of acute coronary syndrome (ACS) is suggestive of critical proximal obstruction of left anterior descending coronary artery (LAD) before its first septal perforator branch (S1). Transient ischemia of the left septal fascicle resulting in left septal fascicular block has been proposed as the causative mechanism. We present a case of acute inferior ST-elevation myocardial infarction caused by acute proximal occlusion of the right coronary artery associated with proximal critical obstruction of the left anterior descending coronary artery.

Severe hypercalcemia from multiple myeloma as an acquired cause of short QT

An otherwise healthy 64-year-old man with recently diagnosed multiple myeloma was admitted to hospital with hypercalcemia and renal failure. Despite his electrocardiogram showing short QT/QTc intervals, he was admitted without cardiac monitoring. He died suddenly a few hours later, likely from a fatal arrhythmia. This case illustrates that pronounced QT shortening from hypercalcemia is an underappreciated malignant finding that can portend a significant risk for arrhythmia and sudden cardiac death. In addition, we also discuss the causes of hypercalcemia associated short QT/QTc intervals and its ECG features.

Left posterior fascicular block, state-of-the-art review: A 2018 update

We conducted a review of the literature regarding epidemiology, clinical, electrocardiographic and vectorcardiographic aspects, classification, and differential diagnosis of left posterior fascicular block. Isolated left posterior fascicular block (LPFB) is an extremely rare finding both in the general population and in specific patient groups. In isolated LPFB 20% of the vectorcardiographic (VCG) QRS loop is located in the right inferior quadrant and when associated with right bundle branch block (RBBB) ≥40%. The diagnosis of LPFB should always consider the clinical aspects, because a definite diagnosis cannot be made in the presence of right ventricular hypertrophy (RVH) (chronic obstructive pulmonary disease (COPD)/emphysema), extensive lateral myocardial infarction (MI) or extremely vertical heart. Intermittent LPFBs are never complete blocks (transient or second degree LPFB) and even in the permanent ones, one cannot be sure that they are complete. When LPFB is associated with RBBB and acute inferior MI, PR interval prolongation is very frequent.

The tetrafascicular nature of the intraventricular conduction system

The existence of a tetrafascicular intraventricular conduction system remains debatable. A consensus statement ended up with some discrepancies and, despite agreeing on the possible existence of an anatomical left septal fascicle, the electrocardiographic and vectorcardiographic characteristics of left septal fascicular block (LSFB) were not universally accepted. The most important criteria requested to confirm the existence of LSFB is its intermittent nature. So far, our group has published cases of transient ischemia‐induced LSFB and phase 4 or bradycardia‐dependent LSFB. Finally, anatomical, anatomopathological, histological, histopathological, electrocardiographic, vectorcardiographic, body surface potential mapping, and electrophysiology studies support the fact that the left bundle branch divides into three fascicles or a “fan‐like interconnected network.”