A study undertaken by researchers at the National Centre for Cardiovascular Research (CNIC) offers novel insights into ventricular fibrillation, the most perilous form of cardiac arrhythmia.
Published in the journal Cardiovascular Research, the investigation reveals that the electrical signals recorded during cardiac arrest caused by ventricular fibrillation yield crucial data about damage to the heart and other vital organs, including the brain.
Ventricular fibrillation stands as a primary contributor to sudden cardiac death. It is estimated that approximately 17,000 instances of sudden cardiac death occur annually in Spain alone, with the majority stemming from malignant arrhythmias such as ventricular fibrillation.
Most episodes of ventricular fibrillation manifest outside of a hospital setting, where survival rates are markedly lower, falling below 10%. This diminished survival is attributable to the fact that the disorganized electrical activity of the ventricles promptly halts effective blood pumping, leading to global ischemia and, if unaddressed, death within minutes.
The research, spearheaded by Dr. David Filgueiras Rama, head of the Advanced Development group on Arrhythmia Mechanisms and Therapies at CNIC, also indicates that the right ventricle possesses a greater capacity than the left to withstand reductions in blood supply and oxygen during cardiac arrest.
“This disparity engenders electrical activation gradients within the heart that track the progression of underlying damage. Furthermore, the surface electrocardiogram (ECG) signal during cardiac arrest linked to ventricular arrhythmia can be employed to predict the likelihood of neurological recovery post-hospitalization,” explains Filgueiras Rama.
The study observed that these differences were more pronounced between the epicardium (the outer layer of the heart) and the endocardium (the inner layer), although distinctions also persisted between the epicardial layers of the right and left ventricles.
The enhanced resilience of the right ventricle was reflected in the prolonged maintenance of its intrinsic electrical activity, aligning with better metabolic preservation and increased resistance to ischemia. These findings were corroborated by computational modeling conducted in collaboration with the Polytechnic University of Valencia.
“Clinical outcomes validate the prognostic significance of the surface ECG in ventricular fibrillation-induced cardiac arrest, demonstrating its potential to identify patients with a higher probability of recovery without severe neurological sequelae,” states Filgueiras Rama.
Jorge García Quintanilla, a senior researcher in the CNIC group and affiliated with CIBERCV, the Spanish Cardiovascular Research Network, adds that “the results obtained provide valuable information that could aid in developing therapeutic strategies aimed at safeguarding the left ventricle and augmenting its resistance to ischemia during cardiac arrest.”
CNIC researcher Andrés Redondo Rodríguez, a co-author of the study and a member of CIBERCV, underscores the importance of interdisciplinary approaches to tackling complex arrhythmia challenges like ventricular fibrillation, fostering the creation of novel treatments in an area that has seen limited progress in recent decades.
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