Heikki V Huikuri

University of Oulu · Department of Internal Medicine

Aims: To evaluate the relationship between spatial heterogeneity of electrocardiographic repolarization and spatial heterogeneity of atrial depolarization with arrhythmic substrate represented by left ventricular fibrosis. Methods and results: We assessed the associations of T- and P-wave morphology parameters analysed from the standard 12-lead...

Background Both electrocardiographic left ventricular hypertrophy (ECG-LVH) and echocardiographic LVH (echo-LVH) are associated with higher risk of cardiovascular and sudden cardiac death. ECG-LVH seems to be partly distinct from echo-LVH as many subjects with echo-LVH do not have ECG-LVH and vice versa. The difference between sexes have not been s...

Background Early identification of individuals at risk of sudden cardiac death (SCD) remains a major challenge. The ECG is a simple, common test, with potential for large‐scale application. We developed and tested the predictive value of a novel index quantifying T‐wave morphologic variations with respect to a normal reference (TMV), which only req...

Aims To evaluate the prognostic significance of the temporal variability of P-wave morphology, specifically in relation to cardiac autonomic regulation. Methods and results We analyzed the standard deviation of P-wave residuum (PWRSD) from five consecutive beats of the standard 12-lead ECG in 1236 patients with angiographically verified coronary a...

Aims To evaluate the prognostic significance of novel P-wave morphology descriptors in general population. Methods and results Novel P-wave morphology variables were analyzed from orthogonal X-, Y-, Z-leads of the digitized electrocardiogram using a custom-made software in 6906 middle-aged subjects of the Mini-Finland Health Survey. A total of 374...

Fragmented QRS (fQRS) is an electrocardiographic (ECG) marker of myocardial conduction abnormality, characterized by additional notches in the QRS complex. The presence of fQRS has been associated with an increased risk of all-cause mortality and arrhythmia in patients with cardiovascular disease. However, current binary visual analysis is prone to...

Background: QRS duration and QTc interval have been associated with sudden cardiac death (SCD), but no data is available on the significance of repolarization component (JTc interval) of QTc as an independent risk marker in the general population. Objective: In this study, we sought to quantify the risk of SCD associated with QRS, QTc and JTc....

Aims Fragmented QRS complex with visible notching on standard 12-lead electrocardiogram (ECG) is understood to represent depolarization abnormalities and to signify risk of cardiac events. Depolarization abnormalities with similar prognostic implications likely exist beyond visual recognition but no technology is presently suitable for quantificati...

Background Poor R wave progression (PRWP) is a common clinical finding in the standard 12-lead ECG, but its prognostic significance is unclear. Objective The purpose of this study was to examine the prognosis associated with PRWP in terms of sudden cardiac death (SCD), cardiac death, and overall mortality in general population subjects with and wi...

Objective: Cardiac hypertrophy with varying degrees of myocardial fibrosis is commonly associated with coronary artery disease (CAD) related sudden cardiac death (SCD), especially in young victims among whom patterns of coronary artery lesions do not entirely appear to explain the cause of SCD. Our aim was to study the genetic background of hypertr...

Introduction Non-ischaemic heart disease (NIHD) is the underlying pathology in∼20% of all sudden cardiac deaths (SCDs). Heavy drinking is known to be associated with SCD due to ischaemic heart disease, but studies on association of recent alcohol consumption and SCD in patients with NIHD are scarce. We evaluated the blood alcohol levels of autopsy...

Aim The association of standard 12-lead electrocardiogram (ECG) markers with benefits of the primary prophylactic implantable cardioverter-defibrillator (ICD) has not been determined in the contemporary era. We analysed traditional and novel ECG variables in a large prospective, controlled primary prophylactic ICD population to assess the predictiv...

The QT interval is an electrocardiographic measure representing the sum of ventricular depolarization (QRS duration) and repolarization (JT interval). Abnormalities of the QT interval are associated with potentially fatal ventricular arrhythmia. We conducted genome-wide multi-ancestry analyses in >250,000 individuals and identified 177, 156 and 121...

Background Negative T-waves are associated with sudden cardiac death (SCD) risk in the general population. Whether flat T-waves also predict SCD is not known. The aim of the study was to examine the clinical characteristics and risk of SCD in general population subjects with flat T-waves. Methods We examined the electrocardiograms of 6750 Finnish...

Coronary artery disease (CAD) mortality has declined substantially over the past decades thanks to advancing medical and interventional/surgical treatments; therefore, the prognostic value of the heart rate variability in CAD in the current treatment era is not well established. We evaluated the prognostic significance of baseline heart rate variab...

The contribution of genetic variants to non-ischemic sudden cardiac death (SCD) due to acquired myocardial diseases is unclear. We studied whether SCD victims with hypertension/obesity related hypertrophic myocardial disease harbor potentially disease associated gene variants. The Fingesture study has collected data from 5869 autopsy-verified SCD v...

Background Cardiac death is one of the leading causes of death and sudden cardiac death (SCD) is estimated to cause approximately 50% of cardiac deaths. Men have a higher cardiac mortality than women. Consequently, the mechanisms and risk markers of cardiac mortality are not as well defined in women as they are in men. Aim The aim of the study was...

Background The possible relationship between temporal variability of electrocardiographic spatial heterogeneity of repolarization and the risk of sudden cardiac death (SCD) in patients with coronary artery disease (CAD) is not completely understood. Methods The standard deviation of T‐wave morphology dispersion (TMD‐SD), of QRST angle (QRSTA‐SD),...

Background: Implantable cardioverter defibrillators (ICDs) prevent sudden cardiac death. ICD implantation decisions are currently based on reduced left ventricular ejection fraction (LVEF≤35%). However, in some patients, the non-arrhythmic death risk predominates thus diminishing ICD-therapy benefits. Based on previous observations, we tested the...

Aims The Cardiac Arrhythmias and RIsk Stratification after Myocardial infArction (CARISMA) study was an observational trial including 312 patients with acute myocardial infarction (MI) and left ventricular ejection fraction (LVEF) <40%. Primary percutaneous intervention (pPCI) was introduced 2 years after start of the enrolment, dividing the popula...

Background Negative T-waves are associated with sudden cardiac death (SCD) in the general population. Whether also low amplitude T-waves link to SCD risk in the general population is unknown. Purpose We investigated the prognostic significance of T-wave abnormalities in a general population cohort. Methods We evaluated the ECGs of 6584 Finnish ge...

Background Carotid intima-media thickness (CIMT) reflects atherogenesis and is a strong predictor of cardiovascular diseases. Although cardiovascular diseases have been shown to originate in foetal life and childhood, the information on the contribution of early growth to CIMT in adulthood remains limited. Purpose To assess the influence of early...

Background Silent myocardial infarctions (SMIs) occur with atypical or no symptoms at all. The burden of SMIs among sudden cardiac death victims have recently been acknowledged. However, the prevalence of previously undetected SMI in young victims remains unclear. Purpose The aim of the present study was to determine the prevalence of autopsy veri...

Background Inferolateral T wave inversion has been associated with increased risk of mortality and sudden cardiac death (SCD) in general population. However, the association between isolated T inversion and SCD is still unclear. Purpose The purpose of this study was to examine whether isolated T inversion associates with SCD, and find out possible...

IntroductionThe prognostic significance of beat-to-beat variability of spatial heterogeneity of repolarization measured from standard 12-lead ECG is not well-understood.Methods We measured the short-term variability of repolarization parameters, such as T-wave heterogeneity in leads V4–V6 (TWH) and QT interval (QT), from five consecutive beats of p...

Aims: Identifying subjects at high and low risk of atrial fibrillation (AF) is of interest. This study aims to assess the risk of AF associated with electrocardiographic (ECG) markers linked to atrial fibrosis: P-wave prolongation, 3rd-degree interatrial block, P-terminal force in lead V1, and orthogonal P-wave morphology. Methods and results: P...

Background Asystole (ASY) and pulseless electrical activity (PEA) have a poor outcome during sudden cardiac arrest (SCA). Psychotropic medication has been associated with a risk for sudden cardiac death (SCD). Our aim was to study the association of psychotropic medication with ASY/PEA during SCA. Methods and results A total of 659 SCA subjects we...

Objectives To evaluate the influence of early growth patterns that have previously been associated with later cardiometabolic risk on cardiac left ventricular (LV) structure and function in midlife. Study design A subpopulation of the Northern Finland Birth Cohort 1966 took part in follow-up, including echocardiography (n = 1155) at the age of 46...

Heart failure (HF) is one of the leading causes of hospitalization in the Western world. Women have a lower HF hospitalization rate and mortality compared to men. The role of electrocardiography as a risk marker of future HF in women is not well known. We studied association of electrocardiographic (ECG) risk factors for HF hospitalization in women...

Funding Acknowledgements Sigrid Juselius Foundation, Finnish Foundation for Cardiovascular Research, Aarne Koskelo Foundation, The Finnish Medical Foundation Background Coronary artery disease (CAD) is the most common underlying cause of sudden cardiac death (SCD). Cardiac hypertrophy with varying amount of myocardial fibrosis is a common risk fac...

Background - The association between leisure time physical activity (LTPA) and the risk of sudden cardiac death (SCD) in coronary artery disease (CAD) patients is not well known. We aim to assess whether there is an association between LTPA and the risk of SCD and non-SCD in CAD patients. Methods - Patients with angiographically verified CAD (n=1,9...

The Task Force for diabetes, pre-diabetes, and cardiovascular diseases of the European Society of Cardiology (ESC) and the European Association for the Study of Diabetes (EASD)

Aims The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter-Defibrillators (EU-CERT-ICD), a prospective investigator-initiated, controlled cohort study, was conducted in 44 centres and 15 European countries. It aimed to assess current clinical effectiveness of primary prevention ICD thera...

Background Fragmented QRS (fQRS) on 12‑lead electrocardiogram (ECG) is associated with scarred myocardium and adverse outcome. However, the data on gender differences in terms of its prevalence and prognostic value is sparse. The aim of this study was to evaluate whether gender differences in fQRS exist among subjects drawn from populations with di...

Background Myocardial scarring from infarction or non-ischemic fibrosis forms an arrhythmogenic substrate. The Selvester QRS-score has been developed to estimate myocardial scar from the 12-lead ECG. Objective We aimed to assess the value of an automated version of the Selvester QRS-score for prediction of ICD therapy and death in patients undergo...

Continuous monitoring of vital signs can be a life‐saving matter for different patient groups. The development is going toward more intelligent and unobtrusive systems to improve the usability of body‐worn monitoring devices. Body‐worn devices can be skin‐conformable, patch‐type monitoring systems that are comfortable to use even for prolonged peri...

Aims: To determine whether the combination of standard electrocardiographic (ECG) markers reflecting domains of arrhythmic risk improves sudden and/or arrhythmic death (SAD) risk stratification in patients with coronary heart disease (CHD). Methods and results: The association between ECG markers and SAD was examined in a derivation cohort (PRED...

Objective A major challenge in reducing the incidence of sudden cardiac death (SCD) is the identification of patients at risk. Myocardial fibrosis has a substantial association with SCD risk but is difficult to identify among general populations. Our aim was to find electrocardiographic (ECG) markers of myocardial fibrosis among SCD victims. Metho...

Background Abnormal 12-lead electrocardiogram (ECG) can predict cardiovascular events, including sudden cardiac death. We tested the hypothesis that ECG provides useful information on guiding implantable cardioverter defibrillator (ICD) therapy into individuals with impaired left ventricular ejection fraction (LVEF). Methods Retrospective data of...

The electrocardiographic (ECG) pattern of early repolarization (ER) and elevated J waves have historically been regarded as benign ECG variants, but during the past few years, this concept has been challenged based on multiple reports linking the ER pattern, or elevated J waves, in the inferior and/or lateral leads of the standard 12-lead ECG with...

In Reply We thank Kuku et al for their interest in our work.¹ They raised important questions related to our article on the prevalence of silent myocardial infarction (SMI) in individuals who experienced sudden cardiac death (SCD) where the underlying cause of death was determined to be coronary artery disease (CAD).¹ The forensic investigation pro...

Objective We investigated whether combining several ECG abnormalities would identify general population subjects with a high sudden cardiac death (SCD) risk. Methods In a sample of 6830 participants (mean age 51.2±13.9 years; 45.5% male) in the Mini-Finland Health Survey, a general population cohort representative of the Finnish adults aged ≥30 ye...

Objectives: To test the hypothesis that age and body mass index (BMI) at BMI peak during infancy and at BMI rebound in childhood are related to cardiovascular autonomic modulation in adulthood. Methods: At the age of 46 years, a sample (n = 5861) of the participants of the Northern Finland Birth Cohort 1966 took part in follow-up examinations. H...

Background: Early repolarization (ER) has been linked to the risk of sudden cardiac death (SCD) in the general population, although controversy remains regarding risks across various subgroups. Objective: We investigated whether age and sex influence the prognostic significance of ER. Methods: We evaluated the 12-lead electrocardiograms of 663...

Background A substantial portion of the risk of atrial fibrillation (AF) remains unexplained by the established risk markers. However, accurate assessment of AF risk would be beneficial, especially among stroke patients and subjects with symptoms attributable to arrhythmia. Purpose To study the associations of P-wave indices with AF risk in the ge...

Background Sudden cardiac death (SCD) remains a major cause of premature mortality worldwide, so there has been an ongoing pursuit for tools for SCD risk stratification. Coronary artery disease is the major cause for SCD in adults, but the level of risk associated with multiple cardiovascular risk factors is not well established. Purpose To create...

Background The possible relationship between temporal variability of electrocardiographic spatial heterogeneity of repolarisation and the risk of sudden cardiac death (SCD) in patients with coronary artery disease (CAD) is not completely understood. Purpose To investigate the prognostic value of temporal variability of T-wave spatial heterogeneity...

Background Heart failure (HF) is one the leading causes of hospitalization in the Western world. Women have a lower rate of HF hospitalization and mortality compared to men. Role of 12-lead electrocardiography (ECG) as a risk marker of future HF in women is not well known. Purpose We studied the association of standard 12-lead ECG and clinical ris...

Background Sudden cardiac death (SCD) is one of the most prevalent cause of death in Western countries representing nearly 20% of total mortality. About 70–80% of SCDs are due to coronary artery disease (CAD). Especially among young victims, whose first cardiac event is often SCD, decent risk prediction and prevention strategies are sadly lacking....

Background Higher cardiac left ventricular (LV) mass (LVM) has independently been associated with cardiovascular risk and mortality. Changes in LV structure have been observed in children with obesity. However, information about the long-term influence of early growth on LV structure is limited. Purpose To explore the associations between early gr...

Background Early repolarization (ER) in the electrocardiogram (ECG) has been associated with increased sudden cardiac death (SCD) risk in the general population. However, controversy remains about the risk associated with ER in different population subgroups. Purpose We evaluated whether age and sex affect the prognostic significance of ER in gene...

Objective To study social and clinical characteristics of victims of sudden cardiac death (SCD) due to alcoholic cardiomyopathy (ACM). Methods The study population comprised a subset of Fingesture cohort. All subjects were verified SCD victims determined to have ACM as cause of death in medico-legal autopsy between 1998 and 2017 in Northern Finlan...

BACKGROUND. The clinical effectiveness of primary prevention implantable cardioverter defibrillator (ICD) therapy is under debate. It is urgently needed to better identify patients who benefit from prophylactic ICD therapy. The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillat...

OBJECTIVE Diabetes increases the risk of all-cause mortality and sudden cardiac death (SCD). The exact mechanisms leading to sudden death in diabetes are not well known. We compared the incidence of appropriate shocks and mortality in patients with versus without diabetes with a prophylactic implantable cardioverter defibrillator (ICD) included in...

Background: The clinical effectiveness of primary prevention implantable cardioverter defibrillator (ICD) therapy is under debate. It is urgently needed to better identify patients who benefit from prophylactic ICD therapy. The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrilla...

Background: A small proportion of patients undergoing primary prophylactic implantation of implantable cardioverter defibrillators (ICDs) experiences malignant arrhythmias. We postulated that periodic repolarisation dynamics, a novel marker of sympathetic-activity-associated repolarisation instability, could be used to identify electrically vulner...

Importance Myocardial infarction in the absence of major or unrecognized symptoms are characterized as silent (SMI). The prevalence of SMI among individuals who experience sudden cardiac death (SCD), with or without concomitant electrocardiographic (ECG) changes, has not previously been described in detail from large studies to our knowledge. Obje...

Introduction: The prognostic significance of P-wave morphology in patients with coronary artery disease (CAD) is not well-known. Methods: A total of 1,946 patients with angiographically verified CAD were included in the Innovation to reduce Cardiovascular Complications of Diabetes at the Intersection (ARTEMIS) study. The P-wave morphology could...

Cardiorespiratory fitness (CRF) and physical activity (PA) are associated with autonomic function but their associations to orthostatic autonomic responses are unclear in epidemiological setting. We hypothesized that higher CRF and PA would associate with higher immediate vagal responses and lower incidence of adverse findings during orthostatic te...

Importance Pacemaker implantations as a treatment for atrioventricular (AV) block are increasing worldwide. Prevention strategies for AV block are lacking because modifiable risk factors have not yet been identified. Objective To identify risk factors for AV block in community-dwelling individuals. Design, Setting, and Participants In this popula...

Objective: To compare cardiac mortality in patients with CAD and prediabetes with that in CAD patients with normal glycemic status and type 2 diabetes. Research design and methods: The Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection (ARTEMIS) study included patients with CAD after revascularization (79%), optima...