Cardiovascular abnormalities in adult patients with the 3243A>G mutation in mitochondrial DNA

Abstract The 3243A>G mutation in mitochondrial DNA (mtDNA), the most common cause of the syndrome of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes, is also associated with many other phenotypes such as hearing loss, diabetes mellitus, epilepsy, cognitive decline, myopathy and cardiomyopathy. The prevalence of the mutation has been shown to be 16.3/100 000 adults in Northern Finland. The present study was performed to estimate the frequency and progression of cardiac abnormalities and to examine causes of death in patients with 3243A>G. Left ventricular hypertrophy (LVH) was found in echocardiography in 56% of patients with 3243A>G and in 15% of age and sex-matched controls. The median thickness of the diastolic interventricular septum or posterior wall was 14 mm in the patients with LVH. The prevalence of LVH determined by echocardiography increased from 40% to 56% in 25 patients with 3243A>G during three years of follow-up, this trend being especially marked among the diabetic patients. The ultra-low-frequency (ULF) and very-low-frequency (VLF) components of the spectral analysis of heart rate variability (HRV) were lower among the patients with 3243A>G than in matched controls (p = 0.02 in ULF and p = 0.04 in VLF), and the short-term fractal scaling exponent in detrended fluctuation analysis of HRV was lower in the patients with 3243A>G (1.16 ± 0.18 vs. 1.28 ± 0.13) (p < 0.01). Survival analysis of a birth cohort from pedigrees with 3243A>G revealed excess mortality before the age of 50 years. Neurological and cardiovascular diseases accounted for 32% of all the underlying causes of death in families with 3243A>G. Death was sudden and unexpected in 31% of cases in which 3243A>G was considered to be involved in the cause of death. The results show that cardiac abnormalities are frequent and progressive in patients with the 3243A>G mtDNA mutation and that cardiac autonomic regulation is disturbed. Patients with the 3243A>G mutation and their first degree maternal relatives died younger than was presupposed by their life expectancy at birth or at 15 years. The most common causes of death were neuropsychiatric and cardiovascular diseases

The OBF database:a large face video database for remote physiological signal measurement and atrial fibrillation detection

Abstract Physiological signals, including heart rate (HR), heart rate variability (HRV), and respiratory frequency (RF) are important indicators of our health, which are usually measured in clinical examinations. Traditional physiological signal measurement often involves contact sensors, which may be inconvenient or cause discomfort in long-term monitoring sessions. Recently, there were studies exploring remote HR measurement from facial videos, and several methods have been proposed. However, previous methods cannot be fairly compared, since they mostly used private, self-collected small datasets as there has been no public benchmark database for the evaluation. Besides, we haven’t found any study that validates such methods for clinical applications yet, e.g., diagnosing cardiac arrhythmias/disease, which could be one major goal of this technology. In this paper, we introduce the Oulu Bio-Face (OBF) database as a benchmark set to fill in the blank. The OBF database includes large number of facial videos with simultaneously recorded reference physiological signals. The data were recorded both from healthy subjects and from patients with atrial fibrillation (AF), which is the most common sustained and widespread cardiac arrhythmia encountered in clinical practice. Accuracy of HR, HRV and RF measured from OBF videos are provided as the baseline results for future evaluation. We also demonstrated that the video-extracted HRV features can achieve promising performance for AF detection, which has never been studied before. From a wider outlook, the remote technology may lead to convenient self-examination in mobile condition for earlier diagnosis of the arrhythmia