Electrical Alternans

ECG Changes Post-pericardiocentesis for Cardiac Tamponade Secondary to Non-small Cell Carcinoma of the Lung

Electrical alternans on electrocardiograph (ECG) is an uncommon but nearly pathognomonic sign of cardiac tamponade. Here, we present a male quadragenarian who came to the emergency department complaining of low back and right upper abdominal pain. Work-up revealed a large pericardial effusion associated with electrical alternans on ECG and clinical findings of cardiac tamponade. Pericardiocentesis drained approximately 1 liter of hemorrhagic fluid with resolution of cardiac tamponade and normalization of the ECG. Further evaluation with right hilar lymph node biopsy confirmed a diagnosis of poorly differentiated non-small cell adenocarcinoma of the lung.

Electrocardiographic Predictors of Complete Heart Block During Right Ventricular Lead Implantation in Patients Who Underwent Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) device procedures have their own complications in addition to the complications associated with standard pacemaker implantations. This study aimed to analyze the predictors of the right bundle branch injury resulting in complete heart block (CHB) during right ventricular (RV) lead implantation in patients who underwent CRT with defibrillator. We conducted an observational study of consecutive 790 patients who underwent CRT with defibrillator device implantation at our institution from 2010 to 2022. Relevant clinical information and complete data regarding the echocardiographic data, implantation procedure, and clinical follow-up were collected into a computerized database. A total of 29 patients (3.7%) had CHB during RV lead implantation. In multivariate analysis, left axis deviation (odds ratio [OR] 2.408, 95% confidence interval [CI] 1.025 to 5.658, p = 0.044), QRS width (OR 1.022, 95% CI 1.001 to 1.043, p = 0.035) and QRS alternans (OR 4.214, 95% CI 1.788 to 9.930, p = 0.001) were found independently related to right bundle branch injury resulting in CHB development during RV lead implantation. In conclusion, left axis deviation, QRS width, and QRS alternans were associated with a higher rate of CHB, and these findings provide insight into optimal and safe CRT device implantation strategies based on preprocedural characteristics.

Tamponnade cardiaque

La tamponnade cardiaque est une urgence vitale. Elle se définit comme une accumulation de liquide dans l’espace intrapéricardique, favorisant une augmentation de la pression intrapéricardique et une altération du remplissage cardiaque. Il s’agit d’une des causes du choc obstructif, et la rapidité d’installation détermine le degré d’instabilité hémodynamique. La morbidité et la mortalité dépendent de la rapidité du diagnostic et de sa prise en charge. Peu fréquemment, l’étiologie est tumorale. Ce type d’étiologie se traduit le plus souvent par des tableaux cliniques d’installation lente et progressive. C’est le cas du sujet qui est présenté dans cet article : un homme de 50 ans sans suivi médical et consommateur d’alcool et de tabac, vivant dans un contexte social difficile. L’issue fatale du cas clinique témoigne de la gravité du tableau de présentation initiale. L’électrocardiogramme peut révéler des signes caractéristiques comme le microvoltage du QRS et l’alternance électrique. La méthode standard pour détecter un épanchement péricardique est l’échocardiographie : le diagnostic de tamponnade cardiaque requiert la présence de collapsus complet du coeur droit et dans les cas plus graves des cavités gauches. Les compétences de l’urgentiste en termes d’échographie permettent un diagnostic plus rapide et précis. Le traitement de la tamponnade cardiaque repose principalement sur le soutien hémodynamique (administration volumique et traitement des éventuels troubles du rythme secondaires) en urgence. Cependant, le traitement définitif reste le drainage du liquide accumulé par péricardiocentèse ou par approche chirurgicale.

Prognosis and role of clinical and imaging features in patients with malignant pericardial effusion: a single-center study in China

Background

The diagnosis of malignant pericardial effusion (MPE) is often associated with a poor prognosis, but due to the complexity and unspecific nature of MPE patients' clinical manifestations, imaging often performs an essential role in diagnosis and prognosis.

Methods

Patients diagnosed with MPE between 2013 and 2018 at one tumor hospital were included and followed up. The data covered the basic clinical features, imaging findings, treatments and prognosis of patients with MPE, and the factors that may have affected the prognosis were explored.

Results

A total of 216 patients with MPE were included with the median age of 60 years. The most common primary cancer type was lung cancer (73.6%), the most common symptom was dyspnea (62.9%) and the most common abnormal electrocardiogram finding was sinus tachycardia (42.1%). The median survival time of the 216 patients with MPE was 13.7 months. The factors affecting prognosis were echocardiographic fluid signs (HR = 2.37, P = 0.010), electrocardiographic evidence of sinus tachycardia (HR = 1.76, P = 0.006) and echocardiographic evidence of cardiac tamponade (HR = 3.33, P < 0.001).

Conclusions

MPE has complex clinical manifestations and an unsatisfactory prognosis. Echocardiographic fluid signs, electrocardiographic evidence of sinus tachycardia, and echocardiographic evidence of cardiac tamponade are independent risk factors affecting prognosis.

[Emergency management of regular supraventricular tachycardias]

With an estimated incidence of approximated 36 per 100,000 persons per year, paroxysmal supraventricular tachycardias form a relevant clinical set of problems. They occur based on different substrates with varied symptoms and electrocardiographic items. The 12-channel ECG depicts the background to determine the underlying pathomechanism. The sinus node and all components of the conduction system such as atrial myocardium can be involved. Vagal maneuvers, several pharmacological strategies and various ablation technology are available for acute therapy.

Total electrical alternans in a patient with malignant pericardial tamponade

We present a case of a 59-year-old man with acute abdominal pain and progressive shortness of breath. A focused assessment with sonography for trauma scan showed free fluid in the hepatorenal recess and in the recto-uterine recess. Later, due to clinical deterioration and the differential possibility of a pulmonary embolism or aortic dissection, a CT scan was performed which revealed large pericardial effusion. This, together with a dilated vena cava inferior and portal system, raised the suspicion of cardiac tamponade. The diagnosis was confirmed by transthoracic echocardiography (TTE). In retrospect, the ECG at admission showed a sinus tachycardia, low-voltage QRS complexes and a total electrical alternans corresponding with the swinging heart seen on TTE. An electrical alternans on ECG is an important diagnostic clue but is often missed, causing an unnecessary delay to proper diagnostic and therapeutic measures.

Tamponade: Hemodynamic and Echocardiographic Diagnosis

Cardiac tamponade is a medical emergency that can be readily reversed with timely recognition and appropriate intervention. The clinical diagnosis of cardiac tamponade requires synthesis of a constellation of otherwise nonspecific features based on an understanding of the underlying pathophysiological characteristics. Although echocardiographic examination is a central component of diagnosis, alone it is insufficient to establish the physiological diagnosis of hemodynamically significant cardiac tamponade. The hemodynamic diagnosis of cardiac tamponade requires clinical evidence of low cardiac output and stroke volume in the setting of elevated cardiac filling pressures, with evidence of increased sympathetic tone (eg, tachycardia, peripheral vasoconstriction), and exclusion of other causes of shock as the primary problem (particularly cardiogenic shock). The hemodynamic features of tamponade are revealed by considering the effects of pericardial constraint. Pulsus paradoxus and loss of the normal "y" descent of a jugular venous pressure waveform may be appreciated on clinical examination. When a pulmonary artery catheter is placed, equalization of diastolic pressures across all chambers is observed. Echocardiographic examination confirms the size, location, and other characteristics of the causal pericardial collection. Several echocardiographic features support the hemodynamic diagnosis of tamponade, including early diastolic collapse of the right ventricle, late diastolic collapse of the right atrium, respiratory variation in mitral valve inflow (akin to pulsus paradoxus), and decreased early filling (E wave) of mitral valve inflow (related to loss of the y descent). Echocardiographic examination then supports decisions about the early treatment and drainage of the tamponading effusion.

Emergencies in Hematology and Oncology

The development of medical emergencies related to the underlying disease or as a result of complications of therapy are common in patients with hematologic or solid tumors. These oncological emergencies can occur as an initial presentation or in a patient with an established diagnosis and are encountered in all medical care settings, ranging from primary care to the emergency department and various subspecialty environments. Therefore, it is critically important that all physicians have a working knowledge of the potential oncological emergencies that may present in their practice and how to provide the most effective care without delay. This article reviews the most common oncological emergencies and provides practical guidance for initial management of these patients.

Alternans of the Ventricular Electrogram in Patients with an Implanted Cardioverter-Defibrillator

BACKGROUND

The occurrence and significance of alternans of the ventricular electrogram (VEGM) in patients with an implanted cardioverter-defibrillator (ICD) has been rarely reported.

OBJECTIVES AND METHODS

This report describes our observations of VEGM alternans documented in nine patients with an ICD (seven new cases and two previously published cases for comparison).

RESULTS

We found seven new cases of near-field VEGM alternans and added two of our previously reported examples. Catecholaminergic polymorphic ventricular tachycardia (CPVT) was diagnosed in one patient based on ICD recordings. Alternans occurred during ventricular tachycardia (VT) in eight patients. A fast sinus tachycardia could not be ruled out in one patient. Stable cycle length alternans was found in five patients. QRS alternans of the left ventricular (LV) electrogram (EGM) was recorded in all five patients who had a device for cardiac resynchronization therapy capable of sensing by the LV channel. These five cases exhibited corresponding alternans of the right ventricular (RV) EGM in three cases, none in one patient, and a questionable recording in another. Alternans of the far-field (FF) VEGM occurred simultaneously with RV EGM alternans in all four patients whose device provided an FF tracing.

CONCLUSION

Ventricular alternans may be more common than realized in ICD patients with VT. The correlation of VEGM alternans with the surface electrocardiogram remains unknown. Although QRS alternans itself as an electrical pattern is generally benign, its cause may not be, as illustrated in our patient with CPVT. Furthermore, associated cycle length alternans or undersensing of the smaller alternans component may complicate ICD therapy.