Lack of temporal correlations between COVID pandemic waves and the occurrence of malignant ventricular arrhythmias.

AIMS: Correlations between malignant ventricular arrhythmias and the COVID waves have never been investigated. METHODS AND RESULTS: Prevalence of malignant ventricular arrhythmias/sudden cardiac death has been correlated to the four COVID waves between the onset of pandemic and end 2021. No significant correlation was present in the temporal evolution of both COVID patients/positive tests and incidence of malignant ventricular arrhythmias, which tended to decrease after vaccination onset. CONCLUSION: We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF.

The real incidence of sudden death: Fair estimations or futile speculations?

BACKGROUND: The true incidence of sudden death remains undetermined, with controversial results from various publications over time and countries. AIM: To investigate if different estimations would reach the values usually reported for France. METHODS: Three different kinds of estimations were used. First, the number of resuscitated sudden deaths and necropsies for sudden death in the Haute-Garonne French administrative department (i.e. county) over the last 10years was expanded to the national level. Second, sudden death coding of death certificates was collected at the national level. Third, the total number of out-of-hospital cardiac arrests leading to any emergency call (with/without intervention) in Haute-Garonne over the last 10years was expanded to the national level. RESULTS: There was a mean of 26 resuscitated sudden deaths and 145 necropsies for sudden death each year in Haute-Garonne, i.e. 12 to 14 sudden deaths for 100,000 inhabitants, and 7700 to 9400 sudden deaths yearly when related to the whole French population, according to the year of inclusion. Based on death certificates, a mean of 6584 sudden deaths was registered each year in France. Finally, there were about 600 yearly calls/interventions for out-of-hospital cardiac arrests in Haute-Garonne, i.e. 40 to 50 sudden deaths for 100,000 inhabitants, and 16,000 to 27,000 sudden deaths yearly for the whole French territory, according to the year of inclusion. CONCLUSIONS: The incidence of sudden death ranges from 6500 to 27,000 in France according to the calculation methods. This huge difference raises the question of the true current incidence of sudden death, which may have been overestimated previously or may be underestimated in France. More straight prospective surveys are needed to solve this question, because of relevant implications for priorities that should be given to sudden death.