Prognostic Significance of Left Anterior Hemiblock in Patients With Suspected Coronary Artery Disease

Comprehensive analysis of right fascicular and right bundle branch blocks: A multi-center study

Electrocardiographic patterns of right bundle branch and fascicular blocks were comprehensively analyzed in a two-phase study. The research aimed to address the scarcity of literature and the absence of standardized diagnostic criteria for these conditions. It revealed a weak correlation between the cardiac axis and age and highlighted the high misdiagnosis rate of these blocks. Furthermore, it discussed the challenges in fulfilling existing diagnostic criteria. The study emphasizes the need for a more precise understanding of right ventricular conduction disorders and the importance of developing robust diagnostic criteria.

Cardiopulmonary predictors of mortality in patients with COVID-19: What are the findings?

BACKGROUND

Since 2019, coronavirus disease 2019 (COVID-19) has been the leading cause of mortality worldwide.

AIMS

To determine independent predictors of mortality in COVID-19, and identify any associations between pulmonary disease severity and cardiac involvement.

METHODS

Clinical, laboratory, electrocardiography and computed tomography (CT) imaging data were collected from 389 consecutive patients with COVID-19. Patients were divided into alive and deceased groups. Independent predictors of mortality were identified. Kaplan-Meier analysis was performed, based on patients having a troponin concentration>99th percentile (cardiac injury) and a CT severity score ≥18.

RESULTS

The mortality rate was 29.3%. Cardiac injury (odds ratio [OR] 2.19, 95% confidence interval [CI] 1.14-4.18; P=0.018), CT score ≥18 (OR 2.24, 95% CI 1.15-4.34; P=0.017), localized ST depression (OR 3.77, 95% CI 1.33-10.67; P=0.012), hemiblocks (OR 3.09, 95% CI 1.47-6.48; P=0.003) and history of leukaemia/lymphoma (OR 3.76, 95% CI 1.37-10.29; P=0.010) were identified as independent predictors of mortality. Additionally, patients with cardiac injury and CT score ≥ 18 were identified to have a significantly shorter survival time (mean 14.21 days, 95% CI 10.45-17.98 days) than all other subgroups. There were no associations between CT severity score and electrocardiogram or cardiac injury in our results.

CONCLUSIONS

Our findings suggest that using CT imaging and electrocardiogram characteristics together can provide a better means of predicting mortality in patients with COVID-19. We identified cardiac injury, CT score ≥18, presence of left or right hemiblocks on initial electrocardiogram, localized ST depression and history of haematological malignancies as independent predictors of mortality in patients with COVID-19.

A Case With Inferior Wall Myocardial Infarction and Conduction Abnormalities: Addressing the Diagnostic Challenges

Conduction disturbances are an important complication of ST-elevation myocardial infarction (STEMI). Conduction disturbances such as fascicular blocks and bundle branch blocks are associated with alteration of QRS morphology and secondary ST-T wave changes that can influence the diagnosis of acute myocardial ischemia. We report an interesting case where a patient presented with inferior wall myocardial infarction (MI), right bundle branch block (RBBB), and left anterior hemiblock (LAHB). We discuss the challenges in diagnosing MI in such patients, including the impact of QRS changes in RBBB and LAHB, their influence on diagnosis of STEMI, and differentiation of combined first-degree AV block and bifascicular block from trifascicular block.

Long-term outcome of intraventricular conduction delays in the general population

Background

Previous population studies have presented conflicting results regarding the prognostic impact of intraventricular conduction delays (IVCD).

Methods

We studied long‐term prognostic impact and the association with comorbidities of eight IVCDs in a random sample of 6,299 Finnish subjects (2,857 men and 3,442 women, mean age 52.8, SD 14.9 years) aged 30 or over who participated in the health examination including 12‐lead ECG. For left bundle branch block (LBBB) and non‐specific IVCD (NSIVCD), two different definitions were used.

Results

During 16.5 years’ follow‐up, 1,309 of the 6,299 subjects (20.8%) died and of these 655 (10.4%) were cardiovascular (CV) deaths. After controlling for known clinical risk factors, the hazard ratio for CV death, compared with individuals without IVCD, was 1.55 for the Minnesota definition of LBBB (95% confidence interval 1.04–2.31, p = .032) and 1.27 (95% confidence interval 0.80–2.02, p = .308) for the Strauss’ definition of LBBB. Subjects with NSIVCD were associated with twofold to threefold increase in CV mortality depending on the definition. While right bundle branch block, left anterior fascicular block and incomplete bundle branch blocks were associated with seemingly higher mortality, this was no longer the case after adjustment for age and sex. The presence of R‐R’ pattern was not associated with any adverse outcome.

Conclusions

In a population study with long‐term follow‐up, NSIVCD and Minnesota definition of LBBB were independently associated with CV mortality. Other IVCDs had no significant impact on prognosis. The prognostic impact of LBBB and NSIVCD was affected by the definition of the conduction disorder.

Electrocardiographic and echocardiographic features in patients with major arterial vascular disease assigned to surgical revascularization

Background: We aimed to depict the electrocardiographic and echocardiographic aspects in patients before elective major vascular surgery.Methods: We evaluated through standard 12 lead electrocardiography and transthoracic echocardiography 469 patients with asymptomatic large abdominal aortic aneurysm (AAA), 334 with critical carotid stenosis (CAS), and 238 with advanced peripheral artery disease (PAD) before surgical revascularization.Results: Patients with AAA were predominantly males (p < .001) with normal sinus rhythm (p = .026), were more affected by atrioventricular block (p = .033) and left anterior fascicular block (p < .001). They also presented larger aortic root size (p < .001) and septal hypertrophy (p = .036), in addition, atrial fibrillation was less frequent in the same group (p = .023). Patients with CAS were of older age (p < .001) with a substantial number of females (p < .001). They presented less left ventricular segmental kinetic disorders and fewer dilated ventricles (p = .004 and p < .001 respectively). Finally, those with PAD had reduced septal and posterior wall thickness (p < .01, p = .009 respectively), greater mitral and aortic annular calcification (p < .001), and were more affected by previous myocardial infarction (p < .001). The PR interval, left anterior fascicular block and aortic root size were independently associated with aneurysm, previous myocardial infarction with PAD, while smaller left ventricular end systolic volumes with carotid artery stenosis.Conclusions: Patients with AAA were mostly affected by cardiac conduction disorders, septal hypertrophy, aortic root dilation and less affected by atrial fibrillation. Patients with CAS were older with more normal sized ventricles, whereas, previous myocardial infarction was most common amongst patients with peripheral artery disease.

Prognostic implications of intraventricular conduction delays in a general population: the Health 2000 Survey

AIMS

We examined the prognostic impact of eight different intraventricular conduction delays (IVCD) in the standard electrocardiogram (ECG) in a community cohort.

METHODS AND RESULTS

Data were collected from 6299 Finnish individuals. During a mean 8.2 years (interquartile range 8.1 to 8.3) of follow-up 640 subjects died (10.2%); 277 (4.4%) were cardiovascular deaths. For both sexes, all-cause and cardiovascular mortality was higher in subjects with IVCD than in those without. In Cox regression analysis after adjustment for age and gender, the hazard ratio for cardiovascular mortality for non-specific IVCD was 4.25 (95% confidence interval [CI] 1.95-9.26, P < 0.0001) and for left bundle branch block (LBBB) 2.11 (95% CI 1.31-3.41, P = 0.002). Right bundle branch block (RBBB) was not related to additional mortality, while incomplete RBBB (IRBBB) presented a hazard ratio of 2.24 (95% CI 1.064-4.77, P = 0.036).

CONCLUSIONS

In the general population, non-specific IVCD, LBBB, and IRBBB were associated with increased relative risk for all-cause and cardiovascular mortality. RBBB did not have an impact on cardiovascular mortality either in subjects with or without previous heart disease.

Usefulness of QRS axis change to predict mortality in patients with left bundle branch block

QRS duration correlates with poor prognosis in patients with left bundle branch block (LBBB), but the importance of left-axis deviation (LAD) is not well established. To determine if LAD confers a mortality risk in patients with LBBB, a single-center, retrospective, population-based cohort study was conducted. Included were all patients at 1 hospital with LBBB on electrocardiography from 1995 to 2005 over a 17-year follow-up period (n = 2,794, median follow-up duration 20 months, interquartile range 6 to 64). Half of all patients with LBBB had LAD. The all-cause mortality rate in the entire cohort was 15%. LAD was not associated with mortality, either as a single outcome (odds ratio [OR] 1.1, 95% confidence interval [CI] 0.88 to 1.3, p = 0.50) or in time-to-event analysis (p = 0.40). Significant risk factors for mortality included high creatinine (OR 1.2, 95% CI 1.1 to 1.3), low hemoglobin (OR 1.2, 95% CI 1.1 to 1.3), history of atrial fibrillation (OR 1.6, 95% CI 1.3 to 2.1), electrocardiographic evidence of previous infarct (OR 1.5, 95% CI 1.2 to 1.9), and history of ventricular tachycardia (OR 1.4, 95% CI 1.0 to 1.9). On bivariate analysis, LAD was associated with atrial fibrillation, ventricular tachycardia, age, and congestive heart failure. Patients with LBBB who converted from normal axis to LAD had significantly higher mortality in time-to-event analysis (p = 0.02). In conclusion, in patients with LBBB, LAD does not confer significant mortality risk. However, those with normal axis who developed LAD during the study period had significantly higher mortality. Perhaps when LBBB and LAD develop concurrently, there is no increased risk over baseline LBBB development, but it may herald a worse prognosis if LAD develops against the background of previous LBBB, from an unknown mechanism.

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

[The evidence-based invasive therapy of stable angina pectoris]

With the spread of invasive cardiology, and with the opening of new home centers today coronarography and the necessary coronary revascularization are accessible for everyone. The indication of invasive investigation of the acute coronary diseases (STEMI, NSTE-ACS) is crystallised by today. At the same time the indication that the invasive strategy of stable coronary disease depends on more factors, this is a complex exercise. This contains the clinical risk stratification (among the analysis of the classic risk factors), and measures the ejection fraction, and the result of the exercise test and the anatomically risk stratification - based on the coronarography. Authors summarised the clinical risk stratification and the indication of the invasive investigation of the stable coronary disease, based on the recent clinical trials and the guidelines.

Association of uncomplicated electrocardiographic conduction blocks with subsequent cardiac morbidity in a community-based population (Olmsted County, Minnesota)

Ventricular conduction blocks (VCBs) identified on a 12-lead electrocardiogram (ECG) are associated with poor outcomes in patients with known cardiac disease. The prognostic implications of uncomplicated VCB (right or left bundle branch block [RBBB or LBBB], left anterior hemiblock) in patients without cardiac diagnoses, however, need to be reevaluated in the current therapeutic era. The purpose of this study was to determine long-term cardiac morbidity and mortality in a community-based population with electrocardiographically-identified VCB, documented normal left ventricular ejection fraction, and no diagnoses of cardiac disease at the time of the index ECG. A retrospective observational cohort study was undertaken of patients in Olmsted County, Minnesota, evaluated from 1975 to 1999. Kaplan-Meier survival analysis post-index electrocardiography was performed with median follow-up of 9.0 years; 706 patients (mean age 64 +/- 16 [SE] years) were identified. Of those, 12% had LBBB with left-axis deviation (LAD); 20% had LBBB without LAD; 26% had left anterior hemiblock; and 42% had RBBB. Kaplan-Meier analysis indicated a significant difference in cardiovascular morbidity risk among the VCB groups (p = 0.017) with left anterior hemiblock and LBBB with LAD, and these were associated with the highest 10-year cardiovascular morbidity risk (58% and 68%, respectively). The incidence of dilated cardiomyopathy was 3% in patients with LBBB with LAD compared with 0.85% in the overall cohort. Significant mortality differences were also demonstrated between LBBB with LAD compared with LBBB without LAD (p = 0.048), left anterior hemiblock compared with LBBB without LAD (p <0.0001), and left anterior hemiblock compared with RBBB (p = 0.0007). In conclusion, the identification of uncomplicated VCB with LAD is associated with increased long-term cardiac morbidity/mortality risk, including the development of dilated and ischemic cardiomyopathy. Isolated VCB is an early marker of cardiac co-morbidities and potentially identifies a high-risk group of patients who warrant preventive intervention.

Electrocardiography: the ECG

This article examines the role of electrocardiography in patient monitoring during an operative procedure. In addition to providing a wealth of physiological information, including information on the electrical activity of the heart, the ECG assists in monitoring and detecting a variety of changes, such as cardiac arrhythmias, electrolyte changes, and ischemia. Information presented on an ECG should be analyzed systematically with an understanding of the constituent elements of an ECG, the rate, the rhythm, the morphology, the axis, the presence of conduction abnormalities, electrolyte changes, and ischemic changes. To assess accurately the information presented, hemodynamic information and cardiac-risk analysis should be integrated to have a complete picture.

Hemiblocks Revisited

The trifascicular nature of the intraventricular conduction system and the concept of trifascicular block and hemiblock were described by Rosenbaum and his coworkers in 1968. Since then, anatomic, pathological, electrophysiological, and clinical studies have confirmed the original description and scarce advances have been developed on the subject. In the present study, we attempt to review and redefine reliable criteria for the electrocardiographic and vectorcardiographic diagnosis of left anterior and posterior hemiblock. One of the most important problems related to hemiblocks is that they may simulate or conceal the electrocardiographic signs of myocardial infarction or myocardial ischemia and may mask or simulate ventricular hypertrophy. Illustrative examples of these associations are shown to help the interpretation of electrocardiograms. The incidence and prevalence of the hemiblocks is presented based on studies performed in hospital patients and general populations. One of the most common causes of hemiblocks is coronary artery disease, and there is a particularly frequent association between anteroseptal myocardial infarction and left anterior hemiblock. The second most important cause is arterial hypertension, followed by cardiomyopathies and Lev and Lenègre diseases. The hemiblocks may also occur in aortic heart disease and congenital cardiopathies. Left anterior hemiblock is more common in men and increases in frequency with advancing age. Evidence is presented regarding the relationship of spontaneous closure of ventricular septal defects, which may explain the finding of this and other conduction defects in young populations. Isolated left anterior hemiblock is a relatively frequent finding in subjects devoid of evidence of structural heart disease. Conversely, isolated left posterior hemiblock is a very rare finding; its prognostic significance is unknown and is commonly associated with right bundle-branch block. The most remarkable feature of this association is that the prognosis is much more serious with a great propensity to develop complete atrioventricular block and Adams-Stoke seizures.