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A lorry driver with chest pain
Published in Tim French, Terry Wardle, The Problem-Based Learning Workbook, 2022
These variables should be monitored every 15 minutes. Continuous ECG monitoring is desirable in this patient. The ECG may show small complexes, or electrical alternans (beat-to-beat alternating height of the QRS complex) in cardiac tamponade.
Regional Ventricular Function in Pulsus Alternans
Published in Samuel Sideman, Rafael Beyar, Analysis and Simulation of the Cardiac System — Ischemia, 2020
I have done some work on electrical alternans in experimental animals by measuring local electrograms in different regions of the epicardium. What I found under similar conditions of myocardial ischemia was that mechanical alternans did not necessarily go along with electrical alternans. The latter is primarily due to altered conduction states. The animal was paced.
Pericardial disease in the elderly
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
ECG findings suggestive of a pericardial effusion are low QRS voltage and electrical alternans. Electrical alternans is usually present in very large pericardial effusions and especially cardiac tamponade and is often accompanied by sinus tachycardia.
Pericardiocentesis by an Air Medical Service for Cardiac Tamponade Caused by Purulent Pericarditis
Published in Prehospital Emergency Care, 2023
Timothy Boardman, Nicholas North, Sara Sullivan
The frequently taught classic presentation of pericardial tamponade is Beck’s triad, which is the presence of muffled heart sounds, jugular venous distention, and hypotension. However, these findings are only found in 24-34%, 53-88%, and 14-35% of cases respectively (3). Other physical exam and diagnostic findings such as pulses paradoxus and electrical alternans on ECG are also variable and are present in a low percentage of cases (3). Point-of-care ultrasound (POCUS) has been shown to be an effective method of diagnosing pericardial tamponade. Systolic right atrial collapse and diastolic right ventricular collapse have high sensitivity and specificity for pericardial tamponade, and right atrial collapse was clearly identified in this case (3). The use of POCUS in the prehospital setting is becoming more widespread, and recent studies have demonstrated that prehospital clinicians can successfully and accurately perform a wide range of ultrasonographic exams (4). Of note, while the flight crew in this case used the emergency department’s ultrasound machine, our program has since purchased a portable ultrasound machine for use on our helicopter.
Acute purulent pericarditis treated conservatively with intrapericardial fibrinolysis and intrapericardial and systemic antibiotics
Published in Baylor University Medical Center Proceedings, 2021
Mahmoud Abdelnabi, Abdallah Almaghraby, Yehia Saleh, Alyaa El Sayed, Judy Rizk
A 65-year-old man, an ex-smoker with a past medical history of type 2 diabetes mellitus, hypertension, and an ischemic stroke 1 year earlier with no residual lag, presented with complaints of acute onset of chest pain, worsening of his baseline dyspnea from grade II to grade III with no orthopnea or paroxysmal nocturnal dyspnea, productive cough, and high-grade fever for a week. He was distressed and tachypneic and had bilateral dilated neck veins. The heart sounds were distant, and coarse crepitations were heard over the left middle and lower lung zones. His heart rate was 110 beats/minute; blood pressure, 80/50 mm Hg; temperature, 39°C; respiratory rate, 25 breaths/minute; and oxygen saturation, 92% on room air. The electrocardiogram revealed sinus tachycardia, deep Q waves in the inferior leads, and low-voltage QRS complexes with electrical alternans. Echocardiography revealed a large circumferential pericardial effusion with early diastolic right ventricular collapse and a dilated noncollapsing inferior vena cava consistent with cardiac tamponade as well as inferior and posterior wall hypokinesia (Video; see Supplementary Material).
Clinical significance of 12 lead ECG changes in patients undergoing pericardiocentesis for cardiac tamponade
Published in Acta Cardiologica, 2021
Avinash Chandra, Gregary D. Marhefka, Matthew V. DeCaro
In our study, of the 19 ECG variables examined, only electrical alternans, low QRS voltage and PR segment depression in the anterior precordial leads changed post-procedure. Historically electrical alternans associated with pericardial effusion has been felt to be indicative of impending or established cardiac tamponade [1]. In our series of 110 patients in which all had cardiac tamponade, only 23% (n = 25) had this finding. It has been suggested that electrical alternans is present only when the heart rate is 100 per minute or greater [1]. This was not seen in our study as at least 40% of these patients (10 of 25) had heart rates less than 100 beats per minute. Electrical alternans is believed to be due to exaggerated, beat-to-beat, anatomical motion of the heart within the pericardial sac enlarged by the massive effusion [5]. If that is the sole cause, electrical alternans should disappear after pericardial drainage [6]. Although reaching statistical significance (Pre: 25 patients vs. Post: 10 patients; p = 0.0011), electrical alternans disappeared in only 60% of patients post procedure. Interestingly, pericarditis was clinically suspected in only five patients (5%) but ST segment elevation was seen in 38% of patients. Acute myocardial infarction was excluded in these patients based on absence of new wall motion abnormalities and three negative troponins. This suggests that ST segment elevation in pericardial tamponade could be a non-specific finding and is of unknown clinical significance. Similarly, PR segment depression only observed in 34% of patients pre-pericardiocentesis, was still present in 22% following the procedure. This finding may be due to persistent pericardial inflammation post-tap.