Objective: In cardiac arrest resulting from ventricular fibrillation, the ventricular fibrillation waveform may be a clue to its duration and predict the likelihood of shock success. However, ventricular fibrillation occurs in different myocardial substrates such as ischemia, heart failure, and structurally normal hearts. We hypothesized that ventricular fibrillation is altered by myocardial infarction and varies from the acute to postmyocardial infarction periods.
Design: An animal intervention study was conducted with comparison to a control group.
Setting: This study took place in a university animal laboratory.
Subjects: Study subjects included 37 swine.
Interventions: Myocardial infarction was induced by occlusion of the midleft anterior descending artery. Ventricular fibrillation was induced in control swine, acute myocardial infarction swine, and in postmyocardial infarction swine after a 2-wk recovery period.
Measurements And Main Results: Ventricular fibrillation was recorded in 11 swine with acute myocardial infarction, ten postmyocardial infarction, and 16 controls. Frequency (mean, median, dominant, and bandwidth) and amplitude-related content (slope, slope-amp [slope divided by amplitude], and amplitude-spectrum area) were analyzed. Frequencies at 5 mins of ventricular fibrillation were altered in both acute myocardial infarction (p < .001 for all frequency characteristics) and postmyocardial infarction swine (p = .015 for mean, .002 for median, .002 for dominant frequency, and <.001 for bandwidth). At 5 mins, median frequency was highest in controls, 10.9 +/- .4 Hz; lowest in acute myocardial infarction, 8.4 +/- .5 Hz; and intermediate in postmyocardial infarction, 9.7 +/- .5 Hz (p < .001 for acute myocardial infarction and p = .002 for postmyocardial infarction compared with control). Slope and amplitude-spectrum area were similar among the three groups with a shallow decline after minute 2, whereas slope-amp remained significantly altered for acute myocardial infarction swine at 5 mins (p = .003).
Conclusions: Ventricular fibrillation frequencies depend on myocardial substrate and evolve from the acute through healing phases of myocardial infarction. Amplitude related measures, however, are similar among these groups. It is unknown how defibrillation may be affected by relying on the ventricular fibrillation waveform without considering myocardial substrate.
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http://dx.doi.org/10.1097/CCM.0b013e31817d798c | DOI Listing |
Int J Cardiol Congenit Heart Dis
March 2024
Department of Cardiovascular Diseases, Mayo Clinic, Jacksonville, FL, USA.
Aims: Patients with D-transposition of the great arteries (D-TGA) and atrial switch experience late morbidity and mortality related to atrial arrhythmias and systemic right ventricular (SRV) failure. We sought to analyze the influence of atrial arrhythmias on long-term outcomes in this group.
Methods: A retrospective review of all patients with D-TGA and atrial switch followed at a tertiary care center was performed.
Aim: The optimal arterial partial pressure of carbon dioxide (PaCO) for patients undergoing extracorporeal cardiopulmonary resuscitation (ECPR) remains unknown. We aimed to investigate the association between post-resuscitation PaCO and neurological outcomes.
Methods: This retrospective cohort study analyzed data from the Study of Advanced Life Support for Ventricular Fibrillation with Extracorporeal Circulation in Japan, a multicenter registry study across 36 hospitals in Japan, including patients with out-of-hospital cardiac arrest (OHCA) admitted to intensive care units (ICU) after ECPR between 2013 and 2018.
Glob Heart
December 2024
Instituto do Coração, Faculdade de Medicina Universidade de São Paulo, São Paulo, Brazil.
Background: Sudden cardiac death (SCD) is a major concern in patients with hypertrophic cardiomyopathy (HCM). The American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) have different guidelines for SCD risk stratification. Their comparative performance in diverse populations remains uncertain.
View Article and Find Full Text PDFIn the early stages of atrial fibrillation (AF), most cases are paroxysmal (pAF), making identification only possible with continuous and prolonged monitoring. With the advent of wearables, smartwatches equipped with photoplethysmographic (PPG) sensors are an ideal approach for continuous monitoring of pAF. There have been numerous studies demonstrating successful capture of pAF events, especially using deep learning.
View Article and Find Full Text PDFHeart Rhythm
December 2024
Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Jerusalem, Israel.
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