Prevalence and prognostic significance of T-wave inversions in right precordial leads of a 12-lead electrocardiogram in the middle-aged subjects

Liver X Receptor Agonist 4β-Hydroxycholesterol as a Prognostic Factor in Coronary Artery Disease

BACKGROUND

Regardless of progress in treatment of coronary artery disease (CAD), there is still a significant residual risk of death in patients with CAD, highlighting the need for additional risk stratification markers. Our previous study provided evidence for a novel blood pressure-regulating mechanism involving 4β-hydroxycholesterol (4βHC), an agonist for liver X receptors, as a hypotensive factor. The aim was to determine the role of 4βHC as a prognostic factor in CAD.

METHODS AND RESULTS

The ARTEMIS (Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection) cohort consists of 1946 patients with CAD. Men and women were analyzed separately in quartiles according to plasma 4βHC. Basic characteristics, medications, ECG, and echocardiography parameters as well as mortality rate were analyzed. At baseline, subjects with a beneficial cardiovascular profile, as assessed with traditional markers such as body mass index, exercise capacity, prevalence of diabetes, and use of antihypertensives, had the highest plasma 4βHC concentrations. However, in men, high plasma 4βHC was associated with all-cause death, cardiac death, and especially sudden cardiac death (SCD) in a median follow-up of 8.8 years. Univariate and comprehensively adjusted hazard ratios for SCD in the highest quartile were 3.76 (95% CI, 1.6-8.7; P=0.002) and 4.18 (95% CI, 1.5-11.4; P=0.005), respectively. In contrast, the association of cardiac death and SCD in women showed the lowest risk in the highest 4βHC quartile.

CONCLUSIONS

High plasma 4βHC concentration was associated with death and especially SCD in men, while an inverse association was detected in women. Our results suggest 4βHC as a novel sex-specific risk marker of cardiac death and especially SCD in chronic CAD.

REGISTRATION INFORMATION

clinicaltrials.gov. Identifier NCT01426685.

The correlation between T-wave abnormalities and adverse cardiovascular events and echocardiographic changes in hypertensive patients

BACKGROUND

Major adverse cardiovascular events (MACE) are common in patients with hypertension and are associated with higher mortality.

METHODS

This study aimed to observe the incidence of MACE in hypertensive patients and the correlation between the electrocardiogram (ECG) T-wave abnormalities and echocardiographic changes. This retrospective cohort study analyzed the incidence of adverse cardiovascular events and changes in echocardiographic features in 430 hypertensive patients admitted to Zhongnan Hospital of Wuhan University from January 2016 to January 2022. Patients were grouped according to a diagnosis of electrocardiographic T-wave abnormalities.

RESULTS

Compared with the normal T-wave group, the incidence of adverse cardiovascular events was significantly higher in hypertensive patients with abnormal T-wave (141 [54.9%] vs 120 [69.4%], x^2 = 9.113, P = .003). However, Kaplan-Meier survival curve showed that no survival advantage was observed in the normal T-wave group at all in the hypertensive patients (P = .83). Echocardiographic values associated with cardiac structural markers, including ascending aorta diameter (AAO), left atrial diameter (LA), and interventricular septal thickness (IVS), were significantly higher in the group with abnormal T-wave than those in the group with normal T-wave at baseline and follow-up (P <.05 for all). In addition, in an exploratory Cox regression analysis model stratified by clinical characteristics of hypertensive patients, the forest plot indicated that the variables, including the age (>65 years), hypertension history (>5 years), premature atrial beats, and severe valvular regurgitation were significantly associated with adverse cardiovascular events (P <.05).

CONCLUSION

Hypertensive patients with abnormal T-wave show a higher incidence of adverse cardiovascular events. The values of cardiac structural markers were significantly higher in the group with abnormal T-wave.

Longitudinal ECG changes among adults with HIV in Tanzania: A prospective cohort study

The prevalence of cardiovascular disease (CVD) is rising among people with HIV (PWH) in sub-Saharan Africa (SSA). Despite the utility of the electrocardiogram (ECG) in screening for CVD, there is limited data regarding longitudinal ECG changes among PWH in SSA. In this study, we aimed to describe ECG changes over a 6-month period in a cohort of PWH in northern Tanzania. Between September 2020 and March 2021, adult PWH were recruited from Majengo HIV Care and Treatment Clinic (MCTC) in Moshi, Tanzania. Trained research assistants surveyed participants and obtained a baseline ECG. Participants then returned to MCTC for a 6-month follow-up, where another ECG was obtained. Two independent physician adjudicators interpreted baseline and follow-up ECGs for rhythm, left ventricular hypertrophy (LVH), bundle branch blocks, ST-segment changes, and T-wave inversion, using standardized criteria. New ECG abnormalities were defined as those that were absent in a patient's baseline ECG but present in their 6-month follow-up ECG. Of 500 enrolled participants, 476 (95.2%) completed follow-up. The mean (± SD) age of participants was 45.7 (± 11.0) years, 351 (73.7%) were female, and 495 (99.8%) were taking antiretroviral therapy. At baseline, 248 (52.1%) participants had one or more ECG abnormalities, the most common of which were LVH (n = 108, 22.7%) and T-wave inversion (n = 89, 18.7%). At six months, 112 (23.5%) participants developed new ECG abnormalities, including 40 (8.0%) cases of new T-wave inversion, 22 (4.6%) cases of new LVH, 12 (2.5%) cases of new ST elevation, and 11 (2.3%) cases of new prolonged QTc. Therefore, new ECG changes were common over a relatively short 6-month period, which suggests that subclinical CVD may develop rapidly in PWH in Tanzania. These data highlight the need for additional studies on CVD in PWH in SSA and the importance of routine CVD screening in this high-risk population.

T-wave Inversions in Precordial Leads: A Case Study of Arrhythmogenic Right Ventricular Cardiomyopathy in a Patient With Recurrent Syncope

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare sudden cardiac death (SCD) syndrome characterized by ventricular arrhythmias of right ventricular (RV) origin. This case follows the presentation of ARVC in an otherwise healthy 26-year-old male. The patient was observed for one week after being admitted from the emergency department secondary to pre-syncope with pathognomonic findings on his electrocardiogram (EKG), echocardiogram, and cardiac imaging. The patient was started on beta-blockers, which ultimately he could not tolerate due to bradycardia, and the recommendation of an automatic implantable cardioverter-defibrillator (AICD) was refused. He was discharged without any complications or ventricular arrhythmias on telemetry while hospitalized.

Outcomes of Investigating T Wave Inversion With Echocardiography in an Unselected Young Male Preparticipation Cohort

BACKGROUND Electrocardiography (ECG) may be performed as part of preparticipation sports screening. Recommendations on screening of athletes to identify individuals with previously unrecognized cardiac disease are robust; however, data guiding the preparticipation screening of unselected populations are scarce. T wave inversion (TWI) on ECG may suggest an undiagnosed cardiomyopathy. This study aims to describe the prevalence of abnormal TWI in an unselected young male cohort and the outcomes of an echocardiography-guided approach to investigating these individuals for structural heart diseases, focusing on the yield for cardiomyopathies. METHODS AND RESULTS Consecutive young male individuals undergoing a national preparticipation cardiac screening program for 39 months were studied. All underwent resting supine 12-lead ECG. Those manifesting abnormal TWI, defined as negatively deflected T waves of at least 0.1 mV amplitude in any 2 contiguous leads, underwent echocardiography. A total of 69 714 male individuals with a mean age of 17.9±1.1 years were studied. Of the individuals, 562 (0.8%) displayed abnormal TWI. This was most frequently observed in the anterior territory and least so in the lateral territory. A total of 12 individuals (2.1%) were diagnosed with a cardiomyopathy. Cardiomyopathy diagnoses were significantly associated with deeper maximum TWI depth and the presence of abnormal TWI in the lateral territory, but not with abnormal TWI in the anterior and inferior territories. No individual presenting with TWI restricted to solely leads V1 to V2, 2 inferior leads or both was diagnosed with a cardiomyopathy. CONCLUSIONS Cardiomyopathy diagnoses were more strongly associated with certain patterns of abnormal TWI. Our findings may support decisions to prioritize echocardiography in these individuals.

Seizure as the clinical presentation of massive pulmonary embolism: Case report and literature review

Massive pulmonary embolism (MPE) is a high-risk medical emergency. Seizure as the clinical presentation of MPE is extremely rare, and to our knowledge, there have been no reports on successful percutaneous, catheter-based treatment of MPE presenting with new-onset seizures and cardiac arrest. In this report, we discuss the case of a 64-year-old woman who presented with an episode of seizure that lasted 5 h. Seizure occurred four times within 12 h after arrival at the hospital, and in the end, she sustained a cardiac arrest. The patient had no past history of seizure or cardiopulmonary disease. Bilateral MPE was detected by a computed tomography pulmonary angiogram, and she was successfully treated with percutaneous, catheter-directed anticoagulant therapy. Pulmonary embolism-related seizures are more difficult to diagnose and have higher mortality rates than seizures. MPE should be suspected in patients presenting with new-onset seizures and hemodynamic instability.

Humanized Dsp ACM Mouse Model Displays Stress-Induced Cardiac Electrical and Structural Phenotypes

Arrhythmogenic cardiomyopathy (ACM) is an inherited disorder characterized by fibro-fatty infiltration with an increased propensity for ventricular arrhythmias and sudden death. Genetic variants in desmosomal genes are associated with ACM. Incomplete penetrance is a common feature in ACM families, complicating the understanding of how external stressors contribute towards disease development. To analyze the dual role of genetics and external stressors on ACM progression, we developed one of the first mouse models of ACM that recapitulates a human variant by introducing the murine equivalent of the human R451G variant into endogenous desmoplakin (DspR451G/+). Mice homozygous for this variant displayed embryonic lethality. While DspR451G/+ mice were viable with reduced expression of DSP, no presentable arrhythmogenic or structural phenotypes were identified at baseline. However, increased afterload resulted in reduced cardiac performance, increased chamber dilation, and accelerated progression to heart failure. In addition, following catecholaminergic challenge, DspR451G/+ mice displayed frequent and prolonged arrhythmic events. Finally, aberrant localization of connexin-43 was noted in the DspR451G/+ mice at baseline, becoming more apparent following cardiac stress via pressure overload. In summary, cardiovascular stress is a key trigger for unmasking both electrical and structural phenotypes in one of the first humanized ACM mouse models.

New Precordial T Wave Inversions in Hospitalized Patients

BACKGROUND

The incidence of precordial T changes has been described in athletes and in specific populations, while the etiology in a large patient population admitted to the hospital has not previously been reported.

METHODS

All electrocardiograms (ECGs) read by the same physician with new (compared to prior ECGs) or presumed new (no prior ECGs) precordial T wave inversions of >1 mm (0.1 mV) in multiple precordial leads were retrospectively reviewed and various ECG, patient-related, and imaging parameters assessed. A total of 226 patients and their ECGs were initially selected for analysis. Of these, 35 were eliminated leaving 191 for the final analysis.

RESULTS

Patients and their ECGs were divided into 5 groups based on diagnosis and incidence including Wellens syndrome, takotsubo, type 2 myocardial infarction, other (including multiple diagnoses), and unknown. Although subtle differences including number of T inversion leads, depth of T waves, QTc intervals, and other variables were present between some groups, diagnosis in individual cases required appropriate clinical, laboratory, or imaging studies. For example, although Wellens syndrome was identified in <20% of cases, a presenting history of chest discomfort with precordial T changes either on the admission or next-day ECG was highly sensitive and specific for this diagnosis. In some cases, type 2 myocardial infarction can also have a Wellens-like ECG phenotype without significant left anterior descending disease.

CONCLUSIONS

Precordial T wave changes in hospitalized patients have various etiologies, and in individual cases, the changes on the ECG alone cannot easily distinguish the presumptive diagnosis and additional data are required.

An idiopathic case of precordial deep T-wave inversion

Introduction and importance

One percent of the patients referred to cardiac intensive care unit (CICU) are presented with T-wave inversion.

Case presentation

We present a case of 78-year-old woman with chest pain and dyspnea. ECG showed precordial deep T-wave inversion.

Clinical discussion

Cardiomyopathies, ischemia and other pathologies were ruled out.

Conclusion

It is likely to be a first reported case of idiopathic deep T-wave inversion seen in the family without any cardiac or non-cardiac etiology.

•

T-wave inversion is commonly presented in electrocardiogram (ECG) of infants.

•

Precordial lead T-wave inversion is seen in infants and can be seen in childhood period as well.

•

Familial clustering of this type of ECG was attractive.

•

Genetic analysis of these findings can give more meaningful conclusions.

Prognostic significance of flat T-waves in the lateral leads in general population

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 general population adults aged ≥30 years and classified the subjects into 3 groups: 1) negative T-waves with an amplitude ≥0.1 mV in ≥2 of the leads I, II, aVL, V4-V6, 2) negative or positive low amplitude T-waves with an amplitude <0.1 mV and the ratio of T-wave and R-wave <10% in ≥2 of the leads I, II, aVL, V4-V6, and 3) normal positive T-waves (not meeting the aforesaid criteria). The association between T-wave classification and SCD was assessed during a 10-year follow-up.

RESULTS

A total of 215 (3.2%) subjects had negative T-waves, 856 (12.7%) flat T-waves, and 5679 (84.1%) normal T-waves. Flat T-wave subjects were older and had more often cardiovascular morbidities compared to normal T-wave subjects, while negative T-wave subjects were the oldest and had most often cardiovascular morbidities. After adjusting for multiple factors, both flat T-waves (hazard ratio [HR] 1.81; 95% confidence interval [CI] 1.13-2.91) and negative T-waves (HR 3.27; 95% CI 1.85-5.78) associated with SCD.

CONCLUSIONS

Cardiovascular risk factors and disease are common among subjects with flat T-waves, but these minor T-wave abnormalities are also independently associated with increased SCD risk.

Association of T-wave abnormalities with major cardiovascular events in diabetes: the ACCORD trial

AIMS/HYPOTHESIS

T-wave abnormalities (TWA) are often found on ECG and signify abnormal ventricular repolarisation. While TWA have been shown to be associated with subclinical atherosclerosis, the relationship between TWA and hard cardiovascular endpoints is less clear and may differ in the presence of diabetes, so we sought to explore these associations in participants from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial.

METHODS

TWA were operationally defined as the presence of any Minnesota Codes 5-1 through 5-4 in any lead distribution. Multivariable Cox proportional hazards models were constructed to examine relationships between TWA and clinical cardiovascular events. Secondary analyses explored the risks conferred by major vs minor TWA, differential effects of TWA by anatomic localisation (anterolateral, inferior or anterior lead distributions), and differing associations in those with or without prevalent CVD.

RESULTS

Among 8176 eligible participants (mean 62.1 ± 6.3 SD years, 61.4% male), there were 3759 cardiovascular events, including 1430 deaths (473 of a cardiovascular aetiology), 474 heart failure events, 1452 major CHD events and 403 strokes. Participants with TWA had increased risks of all-cause mortality (HR 1.45 [95% CI 1.30, 1.62], p < 0.0001), cardiovascular mortality (HR 1.93 [1.59, 2.34], p = 0.0001), congestive heart failure (HR 2.04 [1.69, 2.48], p < 0.0001) and major CHD (HR 1.40 [1.26, 1.57], p < 0.0001), but no increased risk of stroke (HR 0.99 [0.80, 1.23], p = 0.95). Major TWA conferred a higher risk than minor TWA. When TWA were added to the UK Prospective Diabetes Study risk engine, there was improved discrimination for incident CHD events, but only for those with prevalent CVD (area under the receiver operating characteristic curve 0.5744 and 0.6030 with p = 0.0067). Adding TWA to the risk engine yielded improvements in reclassification that were of greater magnitude in those with prevalent CVD (net reclassification improvement [NRI] 0.24 [95% CI 0.16, 0.32] in those with prevalent CVD, NRI 0.14 [95% CI 0.07, 0.22] in those without prevalent CVD).

CONCLUSIONS/INTERPRETATION

The presence and magnitude of TWA are associated with increased risk of clinical cardiovascular events and mortality in individuals with diabetes and may have value in refining risk, particularly in those with prevalent CVD. Graphical abstract.

Electrocardiographic Risk Markers of Cardiac Death: Gender Differences in the General Population

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 to assess the prognostic value and possible gender differences of SCD risk markers of standard 12-lead electrocardiogram in three large general population samples.

Methods

The standard 12-lead electrocardiographic (ECG) markers were analyzed from three different Finnish general population samples including total of 20,310 subjects (49.9% women, mean age 44.8 ± 8.7 years). The primary endpoint was cardiac death, and SCD and all-cause mortality were secondary endpoints. The interaction effect between women and men was assessed for each ECG variable.

Results

During the follow-up (7.7 ± 1.2 years), a total of 883 deaths occurred (24.5% women, p < 0.001). There were 296 cardiac deaths (13.9% women, p < 0.001) and 149 SCDs (14.8% women, p < 0.001). Among those who had died due to cardiac cause, women had more often a normal electrocardiogram compared to men (39.0 vs. 27.5%, p = 0.132). After adjustments with common cardiovascular risk factors and the population sample, the following ECG variables predicted the primary endpoint in men: left ventricular hypertrophy (LVH) with strain pattern (p < 0.001), QRS duration > 110 ms (p < 0.001), inferior or lateral T-wave inversion (p < 0.001) and inferolateral early repolarization (p = 0.033). In women none of the variables remained significant predictors of cardiac death in multivariable analysis, but LVH, QTc ≥ 490 ms and T-wave inversions predicted SCD (p < 0.047 and 0.033, respectively). In the interaction analysis, LVH (HR: 2.4; 95% CI: 1.2–4.9; p = 0.014) was stronger predictor of primary endpoint in women than in men.

Conclusion

Several standard ECG variables provide independent information on the risk of cardiac mortality in men but not in women. LVH and T-wave inversions predict SCD also in women.

Cardiovascular sequalae in uncomplicated COVID-19 survivors

Background

A high proportion of COVID-19 patients were reported to have cardiac involvements. Data pertaining to cardiac sequalae is of urgent importance to define subsequent cardiac surveillance.

Methods

We performed a systematic cardiac screening for 97 consecutive COVID-19 survivors including electrocardiogram (ECG), echocardiography, serum troponin and NT-proBNP assay 1–4 weeks after hospital discharge. Treadmill exercise test and cardiac magnetic resonance imaging (CMR) were performed according to initial screening results.

Results

The mean age was 46.5 ± 18.6 years; 53.6% were men. All were classified with non-severe disease without overt cardiac manifestations and did not require intensive care. Median hospitalization stay was 17 days and median duration from discharge to screening was 11 days. Cardiac abnormalities were detected in 42.3% including sinus bradycardia (29.9%), newly detected T-wave abnormality (8.2%), elevated troponin level (6.2%), newly detected atrial fibrillation (1.0%), and newly detected left ventricular systolic dysfunction with elevated NT-proBNP level (1.0%). Significant sinus bradycardia with heart rate below 50 bpm was detected in 7.2% COVID-19 survivors, which appeared to be self-limiting and recovered over time. For COVID-19 survivors with persistent elevation of troponin level after discharge or newly detected T wave abnormality, echocardiography and CMR did not reveal any evidence of infarct, myocarditis, or left ventricular systolic dysfunction.

Conclusion

Cardiac abnormality is common amongst COVID-survivors with mild disease, which is mostly self-limiting. Nonetheless, cardiac surveillance in form of ECG and/or serum biomarkers may be advisable to detect more severe cardiac involvement including atrial fibrillation and left ventricular dysfunction.

The Changes of T-Wave Amplitude and QT Interval Between the Supine and Orthostatic Electrocardiogram in Children With Dilated Cardiomyopathy

Objectives: Electrocardiogram (ECG) can be affected by autonomic nerves with body position changes. The study aims to explore the ECG changes of children with dilated cardiomyopathy (DCM) when their posture changes. Materials and methods: Sixty-four children diagnosed with DCM were recruited as research group and 55 healthy children as control group. T-wave amplitude and QT interval in ECG were recorded, and their differences between supine and orthostatic ECG were compared in both groups. Subsequently, the children with DCM were followed up and the differences before and after treatment compared. Results: ① Comparisons in differences: Differences of T-wave amplitude in lead II and III, aVF, and V₅ and differences of QT interval in lead II, aVL, aVF, and V₅ were lower in the research group than in the control group. ② Logistic regression analysis and diagnostic test evaluation: The differences of T-wave amplitude in lead III and QT interval in lead aVL may have predictive value for DCM diagnosis. When their values were 0.00 mV and 30 ms, respectively, the sensitivity and specificity of the combined index were 37.5 and 83.6%. ③ Follow-up: In the response group, the T-wave amplitude difference in lead aVR increased and the difference of QT interval in lead V₆ decreased after treatment. In the non-response group, there was no difference before and after treatment. When the combined index of the differences of T-wave amplitude difference in lead aVR and QT interval difference in lead V₆, respectively, were -0.05 mV and 5 ms, the sensitivity and specificity of estimating the prognosis of DCM were 44.4 and 83.3%. Conclusions: The differences of T-wave amplitude and QT interval may have a certain value to estimate DCM diagnosis and prognosis.

T-wave inversion as a manifestation of COVID-19 infection: a case series

Purpose

Cardiac involvement with COVID-19 infection has become evident by elevated troponin, cardiac arrhythmias, ST segment elevation, myocarditis, fulminant heart failure, and sudden cardiac death. We aimed to describe the association of COVID-19 and T-wave inversion (TWI) in a large case series.

Methods

We conducted an observational, retrospective study of confirmed COVID-19 cases with at least one electrocardiogram (ECG) in a large hospital in New York City (March 23, 2020–April 23, 2020). Patients with new TWI or pseudonormalization were further analyzed. Mortality and the need for invasive mechanical ventilation were the main outcomes.

Results

A total of 3225 patients were screened; 195 (6%) were selected for further analysis: 181 with TWI and 14 with T-wave pseudonormalization. Mean age was 66 ± 7 years; 51% were male. TWI were more commonly noted in the lateral (71%), followed by anterior (64%), inferior (57%), and septal (26%) leads. A total of 44 patients (23%) had elevated troponin. A total of 50 patients died (26%). Mortality rates of 35%, and 52% were observed in patients with diffuse TWI, and elevated troponin, respectively. Mortality rate of 80% was observed in patients with both elevated troponin and diffuse TWI. Additionally, 30% of the entire cohort and 58% of patients with elevated troponin required invasive mechanical ventilation.

Conclusion

Our study demonstrates that new TWI is a relatively common finding in COVID-19 patients. Importantly, our findings suggest that new TWI or T-wave pseudonormalization, particularly with elevated troponin, was associated with higher rates of mechanical ventilation and in-hospital mortality.

Supplementary Information

The online version of this article (10.1007/s10840-020-00896-7) contains supplementary material, which is available to authorized users.

Diagnostic and Management Dilemmas in Women Presenting with Acute Coronary Syndromes

PURPOSE OF REVIEW

To summarize gender- and sex-specific differences in the presentation, diagnosis, management, and pathophysiology of women presenting with acute coronary syndrome (ACS).

RECENT FINDINGS

Sex differences exist in many aspects of ACS that impact the identification, treatment, and outcomes in women. There are delays in the initiation of care, under recognized diagnostic differences based on sex, and inconsistencies in the management of ACS in women compared with men, that ultimately impact outcomes. Additionally, women with ACS are more likely than men to present with non-obstructive coronary artery disease (CAD), which appears to be due to diverse underlying pathophysiology. Women with ACS face diagnostic and treatment dilemmas from time of symptom onset to hospital discharge. Under-recognition, under-diagnosis, and under-treatment ultimately result in poorer outcomes in women. Underlying pathophysiologic differences in women require additional testing to elucidate underlying etiologies.

The prognostic significance of T-wave inversion according to ECG lead group during long-term follow-up in the general population

Background

Inverted T waves in the electrocardiogram (ECG) have been associated with coronary heart disease (CHD) and mortality. The pathophysiology and prognostic significance of T‐wave inversion may differ between different anatomical lead groups, but scientific data related to this issue is scarce.

Methods

A representative sample of Finnish subjects (n = 6,354) aged over 30 years underwent a health examination including a 12‐lead ECG in the Health 2000 survey. ECGs with T‐wave inversions were divided into three anatomical lead groups (anterior, lateral, and inferior) and were compared to ECGs with no pathological T‐wave inversions in multivariable‐adjusted Fine–Gray and Cox regression hazard models using CHD and mortality as endpoints.

Results

The follow‐up for both CHD and mortality lasted approximately fifteen years (median value with interquartile ranges between 14.9 and 15.3). In multivariate‐adjusted models, anterior and lateral (but not inferior) T‐wave inversions associated with increased risk of CHD (HR: 2.37 [95% confidence interval 1.20–4.68] and 1.65 [1.27–2.15], respectively). In multivariable analyses, only lateral T‐wave inversions associated with increased risk of mortality in the entire study population (HR 1.51 [1.26–1.81]) as well as among individuals with no CHD at baseline (HR 1.59 [1.29–1.96]).

Conclusions

The prognostic information of inverted T waves differs between anatomical lead groups. T‐wave inversion in the anterior and lateral lead groups is independently associated with the risk of CHD, and lateral T‐wave inversion is also associated with increased risk of mortality. Inverted T wave in the inferior lead group proved to be a benign phenomenon.

Electrocardiographic Risk Markers for Heart Failure in Women Versus Men

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 with 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 from a large middle-aged general population with a long-term follow-up and compared the risk profile to men. Standard 12-lead ECG markers were analyzed from 10,864 subjects (49% women), and their predictive value for HF hospitalization was analyzed. During the follow-up (30 ± 11 years), a total of 1,743 subjects had HF hospitalization; of these, 861 were women (49%). Several baseline characteristics, such as age, body mass index, blood pressure, and history of previous cardiac disease predicted the occurrence of HF both in women and men (p <0.001 for all). After adjusting for baseline variables, ECG sign of left ventricular hypertrophy (LVH) (p <0.001), and atrial fibrillation (p <0.001) were the only baseline ECG variables that predicted future HF in women. In men, HF was predicted by fast heart rate (p = 0.008), T wave inversions (p <0.001), abnormal Q-waves (p = 0.002), and atrial fibrillation (p <0.001). Statistically significant gender interactions in prediction of HF were observed in ECG sign of LVH, inferolateral T wave inversions, and heart rate. In conclusion, ECG sign of LVH predicts future HF in middle-aged women, and T wave inversions and elevated heart rate are associated with HF hospitalization in men.

Prognostic value of myocardial injury-related findings on resting electrocardiography for cardiovascular risk in the asymptomatic general population: the 12-year follow-up report from the Ansan-Ansung cohort

Background: We investigated the predictive values of myocardial injury-related findings (MIFs) including ST-T wave abnormalities (STA) and pathologic Q waves (PQ) in electrocardiography for long-term cardiovascular outcomes in an asymptomatic general population.Methods: We observed 8444 subjects without cardiovascular diseases and related symptoms biennially over a 12-year period. Major cardiovascular adverse events (MACEs) were defined as a composite of cardiovascular death, myocardial infarction, coronary artery disease and stroke.Results: MACEs occurred more frequently in subjects with STA (9.1% vs. 5.2%, p < .001) and in those with anterior PQ (11.5% vs. 5.2%, p = .001) than in those without any MIFs, whereas anterolateral/posterior PQ were not associated with a higher incidence of MACEs. Multivariate Cox regression analyses showed that STA and anterior PQ were independently associated with the risk of MACEs. However, survival receiver operating characteristic curve analysis showed that the composite of STA and anterior PQ did not improve the predictive power of the conventional cardiovascular risk estimators when added to the models.Conclusions: The presence of STA or anterior PQ was associated with worse cardiovascular outcomes in the asymptomatic general population. However, the addition of MIFs to the conventional risk estimators was of limited value in the prediction of MACEs.Key MessagesMyocardial injury-related findings including ST-T wave abnormalities and anterior pathologic Q waves in resting electrocardiography predict long-term cardiovascular outcomes in an asymptomatic low-risk population.However, ST-T wave abnormalities and anterior pathologic Q waves add only limited value to conventional cardiovascular risk estimators in the prediction of cardiovascular outcomes.

The prevalence and correlates of T-wave inversion in lead III in non-obese men

BACKGROUND

T-wave inversion in lead III was linked to displacement of the base of the heart due to abdominal adipose tissue in early electrocardiography (ECG) trials. The observation of T-wave inversion in lead III in some of the pathological and physiological conditions other than obesity suggests the possibilities of different mechanisms. We aimed to investigate the prevalence and correlates of T-wave inversion in lead III in non-obese men.

METHOD

A total of 1240 men underwent ECG, blood pressure measurement, hepatic ultrasonography, and biochemical tests from January 2019 to December 2019. We excluded 220 subjects due to predetermined criteria. The eligible 105 non-obese men with T-wave inversion in lead III and 915 non-obese men without T-wave inversion in lead III were compared with each other in terms of clinical, demographic and laboratory parameters.

RESULTS

The mean age was 27.9 years with a range of 20 to 46 years. The prevalence of T-wave inversion in lead III was 10.3%. Body mass index (BMI), blood urea nitrogen, creatinine, alanine aminotransferase, hematocrit, and the percentage of non-alcoholic fatty liver disease (NAFLD) were significantly higher in Group with T-wave inversion while alkaline phosphatase was significantly higher in Group without T-wave inversion. In multivariable analysis, NAFLD was the best independent correlate of inverted T-wave in lead III (β = 6.215, p < 0.0001). BMI (β = 1.448, p < 0.001) and hematocrit (β = 1.179, p = 0.021) were the other independent correlates of T-wave inversion in lead III.

CONCLUSION

We demonstrated the association of T-wave inversion in lead III with NAFLD, BMI, and hematocrit in non-obese men.

[Association of T-wave amplitude on electrocardiogram with left ventricular ejection fraction in children with dilated cardiomyopathy]

OBJECTIVE

To study the association of T-wave amplitude on electrocardiogram (ECG) with left ventricular ejection fraction (LVEF) in children with dilated cardiomyopathy.

METHODS

A retrospective analysis was performed for the clinical data of 44 children who were diagnosed with dilated cardiomyopathy from May 2009 to June 2018. According to LVEF, they were divided into two groups: LVEF ≥50% group (n=26) and LVEF <50% group (n=18). After treatment, 25 children were followed up for 3-42 months (mean 14±9 months). The Guangdong Zhongshan SR-1000A ECG Automatic Analyzer was used to obtain the 12-lead body surface ECG results in the supine position. T-wave amplitude on ECG was evaluated by software and manual measurement.

RESULTS

Compared with the LVEF ≥50% group, the LVEF <50% group had a significant reduction in the T-wave amplitude in leads II, V4, V5 and V6 (P<0.05). The increased-LVEF group (an increase in LVEF > 5% after treatment) had a significant increase in the T-wave amplitude in leads aVR, V5, and V6 after treatment (P<0.05), while the unchanged-LVEF group (an increase in LVEF ≤ 5% after treatment) had a significant reduction in the T-wave amplitude in lead aVR after treatment (P<0.05). The receiver operating characteristic curve analysis showed that the T-wave amplitude in leads II, V4, V5 and V6 had a certain value in predicting LVEF <50% in children with dilated cardiomyopathy (P<0.05). A combination of T-wave amplitude of ≤0.20 mV in lead II, ≤0.40 mV in lead V4, and ≤0.30 mV in leads V5 and V6 had a sensitivity of 88.2% and specificity of 76.0% in the predication of LVEF <50% in children with dilated cardiomyopathy.

CONCLUSIONS

T-wave amplitude on ECG can be used as the indexes for the evaluation of the left ventricular systolic function in children with dilated cardiomyopathy.

Electrocardiographic associations with myocardial fibrosis among sudden cardiac death victims

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.

METHODS

Study population was acquired from the Fingesture study, which has gathered data from 5869 consecutive autopsied SCD victims in Northern Finland between 1998 and 2017. The degree of fibrosis was determined in histological samples taken from the heart during autopsy and was categorised into four groups: (1) no fibrosis, (2) scattered mild fibrosis, (3) moderate patchy fibrosis and (4) substantial fibrosis. We were able to collect ECGs from 1100 SCD victims.

RESULTS

The mean age of the study subjects was 66±13 years and 75% were male. QRS duration in ECG correlated with the degree of fibrosis (p<0.001, β=0.153). Prevalence of fragmented QRS complex, pathological Q waves and T wave inversions correlated with increased degree of fibrosis (p<0.001 in each). Depolarisation abnormalities were observed both in ischaemic and non-ischaemic heart disease. Repolarisation abnormalities reached statistical significance only among ischaemic SCD victims. An abnormal ECG was observed in 75.3% of the subjects in group 1, 73.7% in group 2, 88.5% in group 3 and 91.7% in group 4 patients (p<0.001).

CONCLUSIONS

Myocardial fibrosis was associated with QRS prolongation, deep Q waves, T wave inversions and QRS fragmentation. The results provide potentially useful non-invasive early recognition of patients with fibrotic cardiomyopathy and risk of SCD.

ECG in dilated cardiomyopathy: specific findings and long-term prognostic significance

OBJECTIVE

The objective was to provide an exhaustive characterization of ECG features in a large cohort of dilated cardiomyopathies (DCMs) and then investigate their possible prognostic role in the long term.

BACKGROUND

ECG is an accessible, reproducible, low-cost diagnostic and prognostic tool. However, an extensive description of ECG features and their long-term prognostic role in a large cohort of DCM is lacking.

METHODS

All available baseline ECGs of DCM patients enrolled from 1992 to 2013 were systematically analysed. Patients underwent to a complete clinical-laboratory evaluation. The study outcome measures were death or heart transplant (D/HT) and sudden death or malignant ventricular arrhythmias (SD/MVA).

RESULTS

Four hundred and fourteen DCM patients were enrolled. During a median follow-up of 125 months, 55 and 57 patients experienced D/HT and SD/MVA, respectively. At multivariate analysis, left ventricular hypertrophy (P = 0.017), heart rate (HR, P = 0.005) and anterolateral T-wave inversion (P = 0.041) predicted D/HT. Regarding SD/MVA, S wave amplitude in V2 (P = 0.008), R wave amplitude in DIII (P = 0.007), anterolateral T-wave inversion (P = 0.017) emerged as predictors. At receiver-operating curve analyses, the addition of ECG models to the clinical-laboratory evaluation significantly increased the area under the curve both for D/HT (from 0.68 to 0.74, P = 0.042) and SD/MVA (from 0.70 to 0.77, P = 0.048).

CONCLUSION

The exhaustive systematic evaluation of ECG has an incremental impact in the prognostication of a large cohort of DCM patients, also regarding the arrhythmic stratification.

Predicting sudden cardiac death in a general population using an electrocardiographic risk score

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 years conducted in 1978-1980, we examined their ECGs, following subjects for 24.3±10.4 years. We analysed the association between individual ECG abnormalities and 10-year SCD risk and developed a risk score using five ECG abnormalities independently associated with SCD risk: heart rate >80 beats per minute, PR duration >220 ms, QRS duration >110 ms, left ventricular hypertrophy and T-wave inversion. We validated the score using an external general population cohort of 10 617 subjects (mean age 44.0±8.5 years; 52.7% male).

RESULTS

No ECG abnormalities were present in 4563 subjects (66.8%), while 96 subjects (1.4%) had ≥3 ECG abnormalities. After adjusting for clinical factors, the SCD risk increased progressively with each additional ECG abnormality. Subjects with ≥3 ECG abnormalities had an HR of 10.23 (95% CI 5.29 to 19.80) for SCD compared with those without abnormalities. The risk score similarly predicted SCD risk in the validation cohort, in which subjects with ≥3 ECG abnormalities had HR 10.82 (95% CI 3.23 to 36.25) for SCD compared with those without abnormalities.

CONCLUSION

The ECG risk score successfully identified general population subjects with a high SCD risk. Combining ECG risk markers may improve the risk stratification for SCD.

ECG changes and markers of increased risk of arrhythmia in patients with myocardial bridge

BACKGROUND

The clinical significance and prognosis of myocardial bridge (MB) is still a matter of debate.

OBJECTIVES

To assess the novel ECG markers of T peak-to-end (Tp-e) interval, transmural dispersion of repolarization (TDR), is assessed by Tp-e/QT ratio, and index of electrophysiogical index(iCEB),is defined by QT/QRS ratio and changes (ST-T changes) in MB patients.

PATIENTS AND METHODS

Forty one patients who were diagnosed as having MB (MB group) and other 41 patients without MB (non-MB group) at multi-detector CT (MDCT) exam matched by age, sex were enrolled in the study.

RESULTS

iCEB was significantly increased in MB group in comparison to non-MB group particularly in patients with no coronary atherosclerosis (5.3 Vs 4.5, p = 0.04). Tp-e and TDR values were decreased in MB in comparison to non-MB patients particularly in patients with coronary atherosclerosis (69 Vs 80, p = 0.003 and 0.18 Vs 0.2, p = 0.01 respectively). Isolated T inversion in V1 was observed more in MB compared to non-MB patients (58% Vs 5%, p ≤ 0.0001) particularly in patients without coronary atherosclerosis.

CONCLUSION

MB patients have shown decreased Tp-e and TDR markers particularly in MB patients with coronary atherosclerosis.

Risk Stratification in Idiopathic Dilated Cardiomyopathy Patients Using Cardiovascular Coupling Analysis

Cardiovascular diseases are one of the most common causes of death; however, the early detection of patients at high risk of sudden cardiac death (SCD) remains an issue. The aim of this study was to analyze the cardio-vascular couplings based on heart rate variability (HRV) and blood pressure variability (BPV) analyses in order to introduce new indices for noninvasive risk stratification in idiopathic dilated cardiomyopathy patients (IDC). High-resolution electrocardiogram (ECG) and continuous noninvasive blood pressure (BP) signals were recorded in 91 IDC patients and 49 healthy subjects (CON). The patients were stratified by their SCD risk as high risk (IDC_HR) when after two years the subject either died or suffered life-threatening complications, and as low risk (IDC_LR) when the subject remained stable during this period. Values were extracted from ECG and BP signals, the beat-to-beat interval, and systolic and diastolic blood pressure, and analyzed using the segmented Poincaré plot analysis (SPPA), the high-resolution joint symbolic dynamics (HRJSD) and the normalized short time partial directed coherence methods. Support vector machine (SVM) models were built to classify these patients according to SCD risk. IDC_HR patients presented lowered HRV and increased BPV compared to both IDC_LR patients and the control subjects, suggesting a decrease in their vagal activity and a compensation of sympathetic activity. Both, the cardio -systolic and -diastolic coupling strength was stronger in high-risk patients when comparing with low-risk patients. The cardio-systolic coupling analysis revealed that the systolic influence on heart rate gets weaker as the risk increases. The SVM IDC_LR vs. IDC_HR model achieved 98.9% accuracy with an area under the curve (AUC) of 0.96. The IDC and the CON groups obtained 93.6% and 0.94 accuracy and AUC, respectively. To simulate a circumstance in which the original status of the subject is unknown, a cascade model was built fusing the aforementioned models, and achieved 94.4% accuracy. In conclusion, this study introduced a novel method for SCD risk stratification for IDC patients based on new indices from coupling analysis and non-linear HRV and BPV. We have uncovered some of the complex interactions within the autonomic regulation in this type of patient.

Electrocardiographic modifications induced by breast implants

Background

Echocardiography realization can be challenging in the presence of breasts implants (BI). It is less known if electrocardiograms (ECG) may be modified in the presence of BI.

Methods

ECG from women with BI (and without any known cardiac structural disease) were sent and analyzed by two experienced electrophysiologists (EP1 and EP2) who were blinded and completely unaware of the context of the patients (Group 1). ECG from a control matched‐group of female women without BI (Group 2) were also blindly sent for analysis.

Results

ECG were collected from 28 women with BI (42 ± 8 years) without any acute medical condition. A proportion of 42% of the ECG were considered abnormal by EP1 and 46% by EP2. The abnormalities were for EP1: negative T waves (5), ST depression in inferolateral leads (2), absence of R wave progression from V1 to V4 (4), left ventricular (LV) hypertrophy (1), long QT(1), early repolarization (1), short PR (1); For EP2: negative T waves (6), ST depression in inferolateral leads (2), absence of R wave progression from V1 to V4 (4), LV hypertrophy(3), long QT (1), early repolarization (1). ECG from group 2 were considered abnormal in only 1 patient (5%) for EP1, and normal in all for EP2 (P = 0.0002 between the groups).

Conclusions

ECG from women with BI were considered abnormal in 42% to 46% of the cases by expert readers. ECG interpretation can thus be misleading in these women.

QRS fragmentation and T-wave inversion as factors of vulnerability to recurrent ventricular tachycardia

Clinical manifestation of late onset recurrent monomorphic ventricular tachycardia (VT) in patients with normal left ventricular ejection fraction may elude diagnosis despite elaborate testing. This report describes a 67-year-old woman with structurally normal heart who presented with recurrent VT in the absence of predisposing factors. Repeated extensive diagnostic testing, including magnetic resonance imaging and coronary angiography, did not disclose any abnormality. An implantable cardioverter-defibrillator was placed following noninducibility of the third episode of VT at electrophysiological study. Patient's 12-lead electrocardiogram in normal sinus rhythm revealed permanent QRS fragmentation as well as T-wave inversions as the only warning features that heralded the impending appearance of recurrent VTs over the course of 5 years follow-up.

Trends in electrocardiographic abnormalities and risk of cardiovascular mortality in Lithuania, 1986-2015

Background

This study aimed to assess the trends in the prevalence of electrocardiographic (ECG) abnormalities from 1986 to 2015 and impact of ECG abnormalities on risk of death from cardiovascular diseases (CVD) in the Lithuanian population aged 40–64 years.

Methods

Data from four surveys carried out in Kaunas city and five randomly selected municipalities of Lithuania were analysed. A resting ECG was recorded and CVD risk factors were measured in each survey. ECG abnormalities were evaluated using Minnesota Code (MC). Trends in age-standardized prevalence of ECG abnormalities were estimated for both sexes. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HR) for coronary heart disease (CHD) and CVD mortality. Net reclassification index (NRI), integrated discrimination improvement and other indices were used for evaluation of improvement in the prediction of CVD and CHD mortality risk after addition of ECG abnormalities variable to Cox models.

Results

From1986 to 2008, the decrease in the prevalence of Q-QS MC was observed in both genders. The prevalence of high R waves increased in men, while the prevalence of ST segment and T wave abnormalities as well as arrhythmias decreased in women. Ischemic changes and possible MI were associated with a 2.5-fold and 4.4-fold higher risk of death from CVD in men and 1.51-fold and 2.56-fold higher mortality risk from CVD in women as compared to individuals with marginal or no ECG abnormalities. The addition of ECG abnormalities to traditional CVD risk factors improved Cox regression models performance. According to NRI, 18.6% of men were correctly reclassified in CVD mortality prediction model and 25.2% of men - in CHD mortality prediction model.

Conclusions

the decreasing trends in the prevalence of ischemia on ECG in women and increasing trends in the prevalence of left VH in men were observed. ECG abnormalities were associated with higher risk of CVD mortality. The addition of ECG abnormalities to the prediction models modestly improved the prediction of CVD mortality beyond traditional CVD risk factors. The use of ECG as routine screening to identify high risk individuals for more intensive preventive interventions warrants further research.

Prevalence and Prognostic Significance of Negative U-waves in a 12-lead Electrocardiogram in the General Population

Negative U-waves are a relatively rare finding in an electrocardiogram (ECG), but are often associated with cardiac disease. The prognostic significance of negative U-waves in the general population is unknown. We evaluated 12-lead ECGs of 6,518 adults (45% male, mean age 50.9 ± 13.8 years) for the presence of U-waves, and followed the subjects for 24.5 ± 10.3 years. Primary end points were all-cause mortality, cardiac mortality, and sudden cardiac death; secondary end point was hospitalization due to cardiac causes. Negative U-waves (amplitude ≥0.05 mV) were present in 231 subjects (3.5%), minor negative (amplitude <0.05 mV) or discordant U-waves in 1,004 subjects (15.4%), normal positive U-waves in 3,950 (60.6%) subjects, and no U-waves were observed in 603 subjects (9.3%). In 730 subjects (11.2%), U-waves were unassessable. When adjusted for age and gender, negative U-waves were associated with all end points (p <0.01). In an analysis adjusted for multiple demographic and clinical factors, in men, negative U-waves were associated with increased risk of all-cause mortality (hazard ratio [HR] 1.60; 95% confidence interval [CI] 1.26 to 2.03; p <0.001), cardiac mortality (HR 1.74; 95% CI 1.26 to 2.39; p = 0.001), and cardiac hospitalization (HR 1.67; 95% CI 1.27 to 2.18; p <0.001), but not with sudden cardiac death, whereas women did not show a significant association to any of the end points (p >0.30). In conclusion, negative U-waves are associated with adverse events in the general population. In men, this association is independent of cardiovascular risk factors.

Comparison between Negative T waves characteristics in acute coronary syndrome and pulmonary embolism

BACKGROUND

Electrocardiogram (ECG) is the first available modality used in patients with chest pain and dyspnea in emergency rooms. We aimed to study differences between acute coronary syndrome (ACS) and acute pulmonary embolism (APE) in patients presented primarily with abnormal negative T waves on their admission Electrocardiogram.

METHODS

This research was a retrospective study in which 297 patients (97 patients with APE and 200 with ACS) were included. The patients were admitted to the emergency ward of a tertiary heart center between 2015 and 2017. In addition to the evaluation of distribution of negative T waves, the depth of the inverted precordial T waves was measured.

RESULTS

The mean age of patients was 62.0 ± 11.4 in ACS group and 60.7 ± 17.6 in APE group (P value = 0.563). Total negative T in V3 and V4 in ACS and APE groups was 9.1 mm and 4.2 mm respectively (P value <0.001). Total magnitude of negative T in anterior leads divided by total magnitude of negative T in inferior leads for ACS and APE groups were 15.1 ± 12.0 and 5.4 ± 3.6 respectively (P value = 0.001). ROC curves showed that total magnitude of negative T in V4 divided by negative T in V1 can be valuable. A cutoff point of 1.75 with sensitivity of 73.5% and specificity of 84.9% (95% CI 0.79-0.91 P < 0.001) could differentiate APE patients from ACS patients.

CONCLUSION

This study suggests that total magnitude of negative T in left precordial leads divided by right precordial leads can be valuable in differentiating APE from ACS.

Pre- and post-exercise electrocardiogram pattern modifications in apparently healthy school adolescents in Cameroon

Background Physical Education and Sport (PES) is compulsory in Cameroonian education system. Cardiac accidents and sudden cardiac deaths (SCD) have been reported during PES examinations. This study aimed to contribute in the prevention of these cardiac accidents by studying pre- and post-exercise electrocardiogram (ECG) pattern modifications in apparently healthy school adolescents. Methods One hundred school adolescents without apparent heart disease [aged 18 ± 2 years; body mass index (BMI): 21.9 ± 2.3] were included. Participants performed two intermittent sprint-endurance tests. The test consisted in walking 2000 m as warm-up, followed by sprint and endurance races. A 12-leads ECG was performed before and in 5 min after the tests. ECG patterns changes were studied with particular attention to abnormalities that could be associated with risk of SCD. Results At rest, ECG patterns variants consisted of bradycardia (30%), sinus arrhythmia (9%), posterior hemi post-block (2%), and early repolarization (3%). which disappeared after exercise in all participants. QTc (ms) and heart rate (HR) increased after exercise (p < 0.001); and RR (ms) decreased post-exercise (p < 0.001). Other changes includes the appearance of the T-waves reversed in precordial leads (V2-V4) (p < 0.001), ventricular (6%), atrial and other supraventricular premature beats (2%) in the post-exercise ECG. Left ventricular hypertrophy (2%), right auricular enlargement (2%), short PR (2%) appeared at the end of the tests. Conclusion This study suggests that an intermittent exercise can induce cardiac abnormalities able to provoke cardiac accidents and SCD in apparently healthy school adolescents.

Prevention of Sudden Cardiac Death in Children and Young Adults

In the present review, we summarize current approaches to the prevention of sudden cardiac death (SCD) in children and young adults, focusing on age less than 35 years. SCD in the young is rare, but devastating from the societal perspective. While coronary artery disease is the main etiology of SCD in the older age groups, conditions such as cardiomyopathies and electrical channelopathies are more likely to be found in the young. In the majority of younger cases, cardiac arrest can be the first recognized manifestation of the underlying cardiac pathology, although some have experienced cardiovascular symptoms prior to the SCD. Since identification of a cardiac disease is pivotal for implementation of appropriate preventive measures, measures such as electrocardiographic screening in subpopulations such as athletes have been proposed. However, these efforts are impeded by the large number of individuals needed to test in order to find one with cardiac disease, leading to significant rates of false positive findings and high costs. When a high-risk cardiac condition is identified in a young person, measures of lifestyle modification, appropriate medical treatment and ICD implantation in selected individuals based on risk stratification are warranted. Nevertheless, the benefits of lifelong ICD therapy need to be balanced with long-term complications and quality of life.

Twelve-lead electrocardiogram and mortality in young adults after ischaemic stroke

Introduction

Ischaemic stroke at young age carries an increased risk for mortality in comparison to the general population, but factors associated with mortality have been poorly studied. We studied the role of electrocardiogram in mortality risk stratification in young stroke patients.

Patients and methods

The Helsinki Young Stroke Registry encompasses 1008 patients aged <50 years with ischaemic stroke. We included 690 patients for this electrocardiogram substudy. Our endpoints were all-cause and cardiovascular mortality. Cox regression models - adjusted for clinical and demographic characteristics - were used to identify the electrocardiogram parameters associated with these endpoints.

Results

At a mean follow-up of 8.8 years, cumulative all-cause and cardiovascular mortality were 16.1 and 9.1%, respectively. Factors associated with both endpoints included diabetes (type 1 for all-cause, type 2 for cardiovascular mortality), heavy drinking, malignancy, as well as stroke severity and aetiology. Of the electrocardiogram parameters, higher heart rate (hazard ratio 1.35 per 10/min, 95% confidence interval 1.21-1.49), a shorter P-wave (hazard ratio 0.78 per 10 ms decrement, 0.64-0.92) and longer QTc interval (1.09 per 10 ms, 1.03-1.16) were associated with increased all-cause mortality. Only a higher heart rate (1.42 per 10/min, 1.24-1.60) was associated with death from cardiovascular causes.

Conclusions

A higher heart rate during the subacute phase after stroke is associated with an elevated risk of all-cause and cardiovascular mortality in young adults. A longer QTc interval is associated only with higher all-cause mortality. P-wave characteristics and their possible association with mortality need further studies.

Long-term follow-up of arrhythmogenic right ventricular cardiomyopathy patients with an implantable cardioverter-defibrillator for prevention of sudden cardiac death

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited cardiomyopathy with a high burden of ventricular arrhythmia, which is an important cause of sudden cardiac death (SCD). Implantable cardioverter-defibrillator (ICD) is believed to be the most reliable management against SCD.

HYPOTHESIS

Ventricular arrhythmia does not necessarily confer a poor prognosis in ARVC patients with an ICD.

METHODS

A total of 39 ARVC patients (34 male) implanted with an ICD at our electrophysiology center and followed up continuously were included in this study. The mean age at diagnosis was 42.1 ± 14.8 years.

RESULTS

Thirty-three patients (84.6%) had suffered ventricular arrhythmia with hemodynamic compromise before ICD implantation. During a median follow-up of 48.6 months (interquartile range, 32.3-73.3), 3 patients (7.7%) died, 1 of sudden death, 1 of heart failure, and 1 of cerebral infarction. Twenty-eight patients (71.8%) experienced 540 appropriate ICD interventions. The first appropriate ICD intervention occurred more than 2 years after initial ICD implantation in 5 patients (12.8%). Twelve patients (30.8%) suffered from electrical storm. The event-free period was significantly shorter in patients who did not have broad precordial T wave inversion ≥V1-V3 (hazard ratio = 0.39, 95% confidence interval: 0.16-0.96). No significant difference was shown in antiarrhythmic drugs and radiofrequency catheter ablation before ICD implantation between patients with and without appropriate ICD therapies (P > 0.05).

CONCLUSIONS

Recurrence of sustained ventricular tachycardia/ventricular fibrillation is frequent in high-risk patients with ARVC. The prognosis is favorable for ARVC patients treated with an ICD for prevention of SCD.

The ability of an electrocardiogram to predict fatal and non-fatal cardiac events in asymptomatic middle-aged subjects

INTRODUCTION

The long-term prognostic value of a standard 12-lead electrocardiogram (ECG) for predicting cardiac events in apparently healthy middle-aged subjects is not well defined.

MATERIALS AND METHODS

A total of 9511 middle-aged subjects (mean age 43 ± 8.2 years, 52% males) without a known cardiac disease and with a follow-up 40 years were included in the study. Fatal and non-fatal cardiac events were collected from the national registries. The predictive value of ECG was separately analyzed for 10 and 30 years. Major ECG abnormalities were classified according to the Minnesota code.

RESULTS

Subjects with major ECG abnormalities (N = 1131) had an increased risk of cardiac death after 10-years (adjusted hazard ratio [HR] 1.7; 95% confidence interval [95% CI], 1.1-2.5, p = 0.009) and 30-years of follow-up (HR 1.3, 95% CI, 1.1-1.5, p < 0.001). Model discrimination measured with the C-index showed only a minor improvement with the inclusion of ECG abnormalities: 0.851 versus 0.853 and 0.742 versus 0.743 for 10- and 30-year follow-up, respectively. ECG did not predict non-fatal cardiac events after 10-years or 30-years of follow-up.

DISCUSSION

Major ECG abnormalities are associated with an increased risk of short and long-term cardiac mortality in middle-aged subjects. However, the improvement in discrimination between subjects with and without fatal cardiac events was marginal with abnormal ECG.

KEY MESSAGES

Abnormalities observed on 12-lead electrocardiogram are shown to have prognostic significance for cardiac events in elderly subjects without known cardiac disease. Our results suggest that ECG abnormalities increase the risk of fatal cardiac events also in middle-aged healthy subjects.

Are 12-lead ECG findings associated with the risk of cardiovascular events after ischemic stroke in young adults?

INTRODUCTION

Ischemic stroke (IS) in a young patient is a disaster and recurrent cardiovascular events could add further impairment. Identifying patients with high risk of such events is therefore important. The prognostic relevance of ECG for this population is unknown.

MATERIALS AND METHODS

A total of 690 IS patients aged 15-49 years were included. A 12-lead ECG was obtained 1-14 d after the onset of stroke. We adjusted for demographic factors, comorbidities, and stroke characteristics, Cox regression models were used to identify independent ECG parameters associated with long-term risks of (1) any cardiovascular event, (2) cardiac events, and (3) recurrent stroke.

RESULTS

Median follow-up time was 8.8 years. About 26.4% of patients experienced a cardiovascular event, 14.5% had cardiac events, and 14.6% recurrent strokes. ECG parameters associated with recurrent cardiovascular events were bundle branch blocks, P-terminal force, left ventricular hypertrophy, and a broader QRS complex. Furthermore, more leftward P-wave axis, prolonged QTc, and P-wave duration >120 ms were associated with increased risks of cardiac events. No ECG parameters were independently associated with recurrent stroke.

CONCLUSION

A 12-lead ECG can be used for risk prediction of cardiovascular events but not for recurrent stroke in young IS patients. KEY MESSAGES ECG is an easy, inexpensive, and useful tool for identifying young ischemic stroke patients with a high risk for recurrent cardiovascular events and it has a statistically significant association with these events even after adjusting for confounding factors. Bundle branch blocks, P-terminal force, broader QRS complex, LVH according to Cornell voltage duration criteria, more leftward P-wave axis, prolonged QTc, and P-wave duration >120 ms are predictors for future cardiovascular or cardiac events in these patients. No ECG parameters were independently associated with recurrent stroke.

Long-term leucine supplementation aggravates prolonged strenuous exercise-induced cardiovascular changes in trained rats

NEW FINDINGS

What is the central question of this study? Can long-term leucine supplementation prevent prolonged strenuous endurance exercise induced cardiac injury? What is the main finding and its importance? Prolonged endurance exercise does not seem to exceed cardiac energetic capacity, hence it does not represent an energy threat to this organ, at least in trained subjects. However, it may induce, in susceptible individuals, a state of cardiac electrical instability, which has been associated with ventricular arrhythmias and sudden cardiac death. This situation might be worsened when combined with leucine supplementation, which leads to increased blood pressure and cardiac injury. Leucine supplementation failed to prevent cardiac fatigue symptoms and may aggravate prolonged strenuous exercise-induced cardiovascular disturbances in trained rats. Observational studies have raised concerns that prolonged strenuous exercise training may be associated with increased risk of cardiac arrhythmia and even primary cardiac arrest or sudden death. It has been demonstrated that leucine can reduce prolonged exercise-induced muscle damage and accelerate the recovery process. The aim of this study was to investigate the effects of prolonged strenuous endurance exercise on cardiovascular parameters and biomarkers of cardiac injury in trained adult male rats and assess the use of leucine as an auxiliary substance to prevent the likely cardiac adverse effects caused by strenuous exercise. Twenty-four male Wistar rats were randomly allocated to receive a balanced control diet (18% protein) or a leucine-rich diet (15% protein plus 3% leucine) for 6 weeks. The rats were submitted to 1 h of exercise, 5 days per week for 6 weeks. Three days after the training period, the rats were submitted to swimming exercise until exhaustion, and cardiac parameters were assessed. Exercising until exhaustion significantly increased cardiac biomarker levels, cytokines and glycogen content inhibited protein synthesis signalling and led to cardiac electrical disturbances. When combined with exercise, leucine supplementation led to greater increases in the aforementioned parameters and also a significant increase in blood pressure and protein degradation signalling. We report, for the first time, that leucine supplementation not only fails to prevent cardiac fatigue symptoms, but may also aggravate prolonged strenuous exercise-induced cardiovascular disturbances in trained rats. Furthermore, we find that exercising until exhaustion can cause cardiac electrical disturbances and damage cardiac myocytes.

Twenty-eight genetic loci associated with ST-T-wave amplitudes of the electrocardiogram

The ST-segment and adjacent T-wave (ST-T wave) amplitudes of the electrocardiogram are quantitative characteristics of cardiac repolarization. Repolarization abnormalities have been linked to ventricular arrhythmias and sudden cardiac death. We performed the first genome-wide association meta-analysis of ST-T-wave amplitudes in up to 37 977 individuals identifying 71 robust genotype–phenotype associations clustered within 28 independent loci. Fifty-four genes were prioritized as candidates underlying the phenotypes, including genes with established roles in the cardiac repolarization phase (SCN5A/SCN10A, KCND3, KCNB1, NOS1AP and HEY2) and others with as yet undefined cardiac function. These associations may provide insights in the spatiotemporal contribution of genetic variation influencing cardiac repolarization and provide novel leads for future functional follow-up.

Body Mass Index as a Predictor of Sudden Cardiac Death and Usefulness of the Electrocardiogram for Risk Stratification

Evidence of the role of body mass index (BMI) as a risk factor for sudden cardiac death (SCD) is conflicting, and how electrocardiographic (ECG) SCD risk markers perform in subjects with different BMIs is not known. In this study, a general population cohort consisting of 10,543 middle-aged subjects (mean age 44 years, 52.7% men) was divided into groups of lean (BMI <20, n = 374), normal weight (BMI 20.0 to 24.9, n = 4,334), overweight (BMI 25.0 to 29.9, n = 4,390), and obese (BMI >30, n = 1,445) subjects. Cox proportional hazards models adjusted for confounders were used to assess the risk for SCD associated with BMI and the risk for SCD associated with ECG abnormalities in subjects with different BMIs. The overweight and obese subjects were at increased risk for SCD (hazard ratios [95% CIs] were 1.33 [1.13 to 1.56], p = 0.001 and 1.79 [1.44 to 2.23], p <0.001 for overweight and obese subjects, respectively). The risk of non-SCD had a similar relation with BMI as SCD. Hazard ratios associated with ECG abnormalities were 3.03, 1.75, 1.74, and 1.34 in groups of lean, normal weight, overweight, and obese subjects, respectively, but no statistical significance was reached in the obese. ECG abnormalities improved integrated discrimination indexes and continuous net reclassification indexes statistically significantly only in the normal weight group. In conclusion, the overweight and obese are at increased risk for SCD but also for non-SCD, and ECG abnormalities are associated with increased risk of SCD also in normal weight subjects presenting with less traditional cardiovascular risk factors.