Electrophysiological ventricular substrate of stroke: a prospective cohort study in the Atherosclerosis Risk in Communities (ARIC) study

ObjectivesThe goal of the study was to determine an association of cardiac ventricular substrate with thrombotic stroke (TS), cardioembolic stroke (ES) and intracerebral haemorrhage (ICH).DesignProspective cohort study.SettingThe Atherosclerosis Risk in Communities (ARIC) study in 1987–1989 enrolled adults (45–64 years), selected as a probability sample from four US communities (Minneapolis, Minnesota; Washington, Maryland; Forsyth, North Carolina; Jackson, Mississippi). Visit 2 was in 1990–1992, visit 3 in 1993–1995, visit 4 in 1996–1998 and visit 5 in 2011–2013.ParticipantsARIC participants with analysable ECGs and no history of stroke were included (n=14 479; age 54±6 y; 55% female; 24% black). Ventricular substrate was characterised by cardiac memory, spatial QRS-T angle (QRS-Ta), sum absolute QRST integral (SAIQRST), spatial ventricular gradient magnitude (SVGmag), premature ventricular contractions (PVCs) and tachycardia-dependent intermittent bundle branch block (TD-IBBB) on 12-lead ECG at visits 1–5.OutcomeAdjudicated TS included a first definite or probable thrombotic cerebral infarction, ES—a first definite or probable non-carotid cardioembolic brain infarction. Definite ICH was included if it was the only stroke event.ResultsOver a median 24.5 years follow-up, there were 899 TS, 400 ES and 120 ICH events. Cox proportional hazard risk models were adjusted for demographics, cardiovascular disease, risk factors, atrial fibrillation, atrial substrate and left ventricular hypertrophy. After adjustment, PVCs (HR 1.72; 95% CI 1.02 to 2.92), QRS-Ta (HR 1.15; 95% CI 1.03 to 1.28), SAIQRST (HR 1.20; 95% CI 1.07 to 1.34) and time-updated SVGmag (HR 1.19; 95% CI 1.08 to 1.32) associated with ES. Similarly, PVCs (HR 1.53; 95% CI 1.03 to 2.26), QRS-Ta (HR 1.08; 95% CI 1.01 to 1.16), SAIQRST (HR 1.07; 95% CI 1.01 to 1.14) and time-updated SVGmag (HR 1.11; 95% CI 1.04 to 1.19) associated with TS. TD-IBBB (HR 3.28; 95% CI 1.03 to 10.46) and time-updated SVGmag (HR 1.23; 95% CI 1.03 to 1.47) were associated with ICH.ConclusionsPVC burden (reflected by cardiac memory) is associated with ischaemic stroke. Transient cardiac memory (likely through TD-IBBB) precedes ICH.

Does Ventricular Substrate Play a Role in Incident Stroke? The Atherosclerosis Risk in Communities (ARIC) Study

Background—The goal of the study was to determine an association of ventricular substrate with thrombotic, cardioembolic, and hemorrhagic stroke.Methods—Participants from the Atherosclerosis Risk in Communities study with analyzable ECGs and no history of stroke were included (n=14,479; age 54±6 y; 55% female; 24% black). Ventricular substrate was characterized by cardiac memory [spatial QRS-T angle (QRS-Ta), sum absolute QRST integral (SAIQRST), spatial ventricular gradient magnitude (SVGmag)], premature ventricular contractions (PVC) and tachycardia-dependent intermittent bundle branch block (TD-IBBB) on 12-lead ECG recorded at visits 1-5. Incident strokes were adjudicated by physician reviewers. Cox proportional hazard risk models were constructed.Results—Over a median 24.5 y follow-up, there were 899 thrombotic, 400 cardioembolic, and 187 hemorrhagic strokes. After adjustment for cardiovascular disease (CVD) and its risk factors, atrial fibrillation / atrial substrate, and ECG-left ventricular hypertrophy, PVC (HR 1.72; 95%CI 1.02-2.92), QRS-Ta (HR 1.15; 95%CI 1.03-1.28), SAIQRST (HR 1.20; 95%CI 1.07-1.34) and time-updated SVGmag (HR 1.19; 95%CI 1.08-1.32) associated with cardioembolic stroke. After adjustment for CVD and its risk factors, PVC (HR 1.53; 95%CI 1.03-2.26), QRS-Ta (HR 1.08; 95%CI 1.01-1.16), SAIQRST (HR 1.07; 95%CI 1.01-1.14), and time-updated SVGmag (HR 1.11; 95%CI 1.04-1.19) associated with thrombotic stroke. In fully adjusted time-updated Cox model QRS-Ta (HR 1.20; 95%CI 1.04-1.38), SAI QRST (HR 1.23; 95%CI 1.06-1.43), SVGmag (HR 1.23; 95%CI 1.06-1.43) associated with hemorrhagic stroke, whereas TD-IBBB trended (HR 1.84; 95%CI 0.25-13.33).Conclusions—PVC burden reflected by cardiac memory is associated with ischemic stroke. Transient cardiac memory (likely through TD-IBBB) precedes hemorrhagic stroke.

T-wave inversion in the precordial leads: сardiac and non-cardiac causes

The T-wave inversion (TWI) is a common electrocardiographic finding. Causes for TWI are numerous and sometimes TWI may appear in life-threatening conditions. The aim of this review was to provide an up-to-date analysis of TWI, including i) definition and prevalence; ii) causes, and iii) differential diagnosis in benign TWI, reversible myocardial ischemia of the left ventricular anterior wall; takotsubo cardiomyopathy; subarachnoid hemorrhage; pulmonary embolism; right ventricular arrhythmogenic cardiomyopathy; and “cardiac memory”. The review presents practical electrophysiological criteria, which allow suspecting in time a life-threatening condition to choose an up-to-date treatment.

Cardiac Memory-induced T-wave Inversions

Introduction: Cardiac memory refers to T-wave inversions that result when normal ventricular activation resumes following a period of abnormal ventricular activation. Case Report: We present a case of a 29-year-old man with a pacemaker who presented with new, deep symmetric T-wave inversions caused by cardiac memory. Discussion: Abnormal ventricular activation is most commonly induced by ventricular pacing but can also occur in the setting of transient left bundle branch blocks, ventricular tachycardia, and intermittent ventricular pre-excitation. Conclusion: Recognition of this phenomenon may help to reduce unnecessary admissions, cardiac testing, and cardiac catheterizations.