M Malik1, A J Camm. 1. Department of Cardiological Sciences, St George's Hospital Medical School, London.
Abstract
STUDY OBJECTIVE: The study examined heart rate variability to find out whether shorter ECG records can predict long term mortality following acute myocardial infarction as efficiently as 24 h recordings. DESIGN: Heart rate variability was assessed in 24 h electrocardiograms recorded during the first 2 weeks following acute myocardial infarction and in separate 1 h portions of the complete recording. The spectral analysis of complete 24 h records was performed and different short and long term components of heart rate variability were used to distinguish between patients with and without later complications. SUBJECTS: 20 patients who initially survived acute myocardial infarction but later experienced serious events (death or symptomatic sustained ventricular tachycardia) during a 6 month follow up (group I) were compared with 20 patients (group II) who remained free of complications for more than 6 months after discharge and who were matched with group I for age, gender, infarct site, ejection fraction, and beta blocker treatment. MEASUREMENTS AND MAIN RESULTS: The distinction based on components limited to changes of heart rate within periods less than or equal to 1 h was as significant (p less than 0.001, paired t test) as when using the components limited to changes of periods less than or equal to 10 h. However, heart rate variability of separate 1 h portions of the complete 24 h records differed between the groups significantly only for certain 1 h intervals of the day (the p values varied from 0.2 to 0.0005). CONCLUSIONS: Whilst the maximum value of short term heart rate variability is sufficient for stratification of the high risk post-myocardial infarction patients, an arbitrarily selected short term ECG recording is unlikely to register the maximum heart rate variability. It is concluded that the heart rate variability assessed from arbitrary 1 h electrocardiographic records is not as prognostically important as the variability estimated from 24 h recordings.
STUDY OBJECTIVE: The study examined heart rate variability to find out whether shorter ECG records can predict long term mortality following acute myocardial infarction as efficiently as 24 h recordings. DESIGN: Heart rate variability was assessed in 24 h electrocardiograms recorded during the first 2 weeks following acute myocardial infarction and in separate 1 h portions of the complete recording. The spectral analysis of complete 24 h records was performed and different short and long term components of heart rate variability were used to distinguish between patients with and without later complications. SUBJECTS: 20 patients who initially survived acute myocardial infarction but later experienced serious events (death or symptomatic sustained ventricular tachycardia) during a 6 month follow up (group I) were compared with 20 patients (group II) who remained free of complications for more than 6 months after discharge and who were matched with group I for age, gender, infarct site, ejection fraction, and beta blocker treatment. MEASUREMENTS AND MAIN RESULTS: The distinction based on components limited to changes of heart rate within periods less than or equal to 1 h was as significant (p less than 0.001, paired t test) as when using the components limited to changes of periods less than or equal to 10 h. However, heart rate variability of separate 1 h portions of the complete 24 h records differed between the groups significantly only for certain 1 h intervals of the day (the p values varied from 0.2 to 0.0005). CONCLUSIONS: Whilst the maximum value of short term heart rate variability is sufficient for stratification of the high risk post-myocardial infarctionpatients, an arbitrarily selected short term ECG recording is unlikely to register the maximum heart rate variability. It is concluded that the heart rate variability assessed from arbitrary 1 h electrocardiographic records is not as prognostically important as the variability estimated from 24 h recordings.
Authors: Anton R Kiselev; Vladimir I Gridnev; Mikhail D Prokhorov; Anatoly S Karavaev; Olga M Posnenkova; Vladimir I Ponomarenko; Boris P Bezruchko; Vladimir A Shvartz Journal: Ann Noninvasive Electrocardiol Date: 2012-07 Impact factor: 1.468
Authors: Emma Karey; Shiyue Pan; Amber N Morris; Donald A Bruun; Pamela J Lein; Chao-Yin Chen Journal: Front Physiol Date: 2019-06-06 Impact factor: 4.566