Fragmented QRS complexes on 12-lead ECG: a marker of cardiac sarcoidosis as detected by gadolinium cardiac magnetic resonance imaging

A Comprehensive Review on the Electrocardiographic Manifestations of Cardiac Sarcoidosis: Patterns and Prognosis

PURPOSE OF REVIEW

Cardiac sarcoidosis (CS) refers to cardiac involvement in sarcoidosis and is usually associated with worse outcomes. This comprehensive review aims to elucidate the electrocardiographic (ECG) signs and features associated with CS, as well as examine modern techniques and their importance in CS evaluation.

RECENT FINDINGS

The exact pathogenesis of CS is still unclear, but it stems from an abnormal immunological response triggered by environmental factors in individuals with genetic predisposition. CS presents with non-cardiac symptoms; however, conduction system abnormalities are common in patients with CS. The most common electrocardiographic (ECG) signs include atrioventricular blocks and ventricular tachyarrhythmia. Distinct patterns, such as fragmented QRS complexes, T-wave alternans, and bundle branch blocks, are critical indicators of myocardial involvement. The application of advanced ECG techniques such as signal-averaged ECG, Holter monitoring, wavelet-transformed ECG, microvolt T-wave alternans, and artificial intelligence-supported analysis holds promising outcomes for opportune detection and monitoring of CS. Timely utilisation of inexpensive and readily available ECG possesses the potential to allow early detection and intervention for CS. The integration of artificial intelligence models into ECG analysis is a promising approach for improving the ECG diagnostic accuracy and further risk stratification of patients with CS.

Management of cardiac sarcoidosis

Cardiac sarcoidosis (CS) is a form of inflammatory cardiomyopathy associated with significant clinical complications such as high-degree atrioventricular block, ventricular tachycardia, and heart failure as well as sudden cardiac death. It is therefore important to provide an expert consensus statement summarizing the role of different available diagnostic tools and emphasizing the importance of a multidisciplinary approach. By integrating clinical information and the results of diagnostic tests, an accurate, validated, and timely diagnosis can be made, while alternative diagnoses can be reasonably excluded. This clinical expert consensus statement reviews the evidence on the management of different CS manifestations and provides advice to practicing clinicians in the field on the role of immunosuppression and the treatment of cardiac complications based on limited published data and the experience of international CS experts. The monitoring and risk stratification of patients with CS is also covered, while controversies and future research needs are explored.

The International Criteria for Electrocardiogram Interpretation in Athletes: Common Pitfalls and Future Directions

Preparticipation cardiovascular screening (PPCS) in young athletes is performed to detect conditions associated with sudden cardiac death. Many medical societies and sports governing bodies support the addition of a 12-lead electrocardiogram (ECG) to the history and physical to improve PPCS sensitivity. The current standard for ECG interpretation in athletes, the International Criteria, was developed to distinguish physiologic from pathologic ECG findings in athletes. Although application of the International Criteria has reduced the PPCS false-positive rate, interpretative challenges and potential areas of improvement remain. This review provides an overview of common pitfalls and future directions for ECG interpretation in athletes.

The Fragmented QRS Complex in Lead V1: Time for an Update of the Athlete's ECG?

Differentiating between ECG patterns related to athletes' heart remodeling and pathological findings is a challenge in sports cardiology. As the significance of fragmented complex in athletes remains uncertain, this study aimed to assess the presence of fragmented QRS in lead V1 (fQRSV1) among young athletes and its association with heart adaptations and arrhythmias. Young athletes referred for annual pre-participation screening receiving a maximal exercise testing and transthoracic echocardiography from January 2015 to March 2021 were included. The study included 684 young athletes. The prevalence of fQRSV1 was 33%. Subjects with fQRSV1 had higher exercise capacity and indexes of right ventricular function and remodeling. Among highly trained athletes, the fQRSV1 group demonstrated also increased left ventricular wall thickness. No significant association existed between fQRSV1 and exercise-induced arrhythmias, even in highly trained athletes. The high prevalence of fQRSV1 in young athletes is associated with training-induced heart adaptations but not exercise-induced ventricular arrhythmias.

QRS fragmentation does not predict mortality in survivors of acute myocardial infarction

BACKGROUND

Despite advances in coronary revascularization and in heart failure management, myocardial infarction survivors remain at substantially increased mortality risk. Precise risk assessment and risk-adapted follow-up care are crucial to improve their outcomes. Recently, the fragmented QRS complex, i.e. the presence of additional spikes within the QRS complexes on a 12-lead electrocardiogram, has been discussed as a potential non-invasive risk predictor in cardiac patients.

HYPOTHESIS

The aim of this study was to evaluate the prognostic meaning of the fragmented QRS complex in myocardial infarction survivors.

METHODS

609 patients with narrow QRS complexes <120 ms were included in a prospective cohort study while hospitalized for myocardial infarction and followed for 5 years.

RESULTS

The prevalence of the fragmented QRS complex in these patients amounted to 46.8% (285 patients). These patients had no increased hazard of all-cause death (HR 0.84, 95%-CI 0.45-1.57, p = 0.582) with a mortality rate of 6.0% compared to 7.1% in patients without QRS fragmentations. Furthermore, the risks of cardiac death (HR 1.28, 95%-CI 0.49-3.31, p = 0.613) and of non-cardiac death (HR 0.6, 95%-CI 0.26-1.43, p = 0.25) were not significantly different in patients with QRS fragmentations. However, patients with QRS fragmentations had increased serum creatine kinase concentrations (1438U/l vs. 1160U/l, p = 0.039) and reduced left ventricular ejection fractions (52% vs. 54%, p = 0.011).

CONCLUSIONS

The hypothesis that QRS fragmentation might be a prognostic parameter in survivors of myocardial infarction was not confirmed. But those with QRS fragmentation had larger myocardial infarctions, as measured by creatine kinase and left ventricular ejection fraction.

Electrocardiographic abnormalities in patients with cardiomyopathies

Abnormalities in impulse generation and transmission are among the first signs of cardiac remodeling in cardiomyopathies. Accordingly, 12-lead electrocardiogram (ECG) of patients with cardiomyopathies may show multiple abnormalities. Some findings are suggestive of specific disorders, such as the discrepancy between QRS voltages and left ventricular (LV) mass for cardiac amyloidosis or the inverted T waves in the right precordial leads for arrhythmogenic cardiomyopathy. Other findings are less sensitive and/or specific, but may orient toward a specific diagnosis in a patient with a specific phenotype, such as an increased LV wall thickness or a dilated LV. A "cardiomyopathy-oriented" mindset to ECG reading is important to detect the possible signs of an underlying cardiomyopathy and to interpret correctly the meaning of these alterations, which differs in patients with cardiomyopathies or other conditions.

The pivotal role of ECG in cardiomyopathies

Cardiomyopathies are a heterogeneous group of pathologies characterized by structural and functional alterations of the heart. Recent technological advances in cardiovascular imaging offer an opportunity for deep phenotypic and etiological definition. Electrocardiogram (ECG) is the first-line diagnostic tool in the evaluation of both asymptomatic and symptomatic individuals. Some electrocardiographic signs are pathognomonic or fall within validated diagnostic criteria of individual cardiomyopathy such as the inverted T waves in right precordial leads (V1-V3) or beyond in individuals with complete pubertal development in the absence of complete right bundle branch block for the diagnosis of arrhythmogenic cardiomyopathy of the right ventricle (ARVC) or the presence of low voltages typically seen in more than 60% of patients with amyloidosis. Most other electrocardiographic findings such as the presence of depolarization changes including QRS fragmentation, the presence of epsilon wave, the presence of reduced or increased voltages as well as alterations in the repolarization phase including the negative T waves in the lateral leads, or the profound inversion of the T waves or downsloping of the ST tract are more non-specific signs which can however raise the clinical suspicion of cardiomyopathy in order to initiate a diagnostic procedure especially using imaging techniques for diagnostic confirmation. Such electrocardiographic alterations not only have a counterpart in imaging investigations such as evidence of late gadolinium enhancement on magnetic resonance imaging, but may also have an important prognostic value once a definite diagnosis has been made. In addition, the presence of electrical stimulus conduction disturbances or advanced atrioventricular blocks that can be seen especially in conditions such as cardiac amyloidosis or sarcoidosis, or the presence of left bundle branch block or posterior fascicular block in dilated or arrhythmogenic left ventricular cardiomyopathies are recognized as a possible expression of advanced pathology. Similarly, the presence of ventricular arrhythmias with typical patterns such as non-sustained or sustained ventricular tachycardia of LBBB morphology in ARVC or non-sustained or sustained ventricular tachycardia with an RBBB morphology (excluding the "fascicular pattern") in arrhythmogenic left ventricle cardiomyopathy could have a significant impact on the course of each disease. It is therefore clear that a learned and careful interpretation of ECG features can raise suspicion of the presence of a cardiomyopathy, identify diagnostic "red flags" useful for orienting the diagnosis toward specific forms, and provide useful tools for risk stratification. The purpose of this review is to emphasize the important role of the ECG in the diagnostic workup, describing the main ECG findings of different cardiomyopathies.

The International Criteria for Electrocardiogram Interpretation in Athletes: Common Pitfalls and Future Directions

Preparticipation cardiovascular screening (PPCS) in young athletes is performed to detect conditions associated with sudden cardiac death. Many medical societies and sports governing bodies support the addition of a 12-lead electrocardiogram (ECG) to the history and physical to improve PPCS sensitivity. The current standard for ECG interpretation in athletes, the International Criteria, was developed to distinguish physiologic from pathologic ECG findings in athletes. Although application of the International Criteria has reduced the PPCS false-positive rate, interpretative challenges and potential areas of improvement remain. This review provides an overview of common pitfalls and future directions for ECG interpretation in athletes.

Fragmented QRS on 12-lead electrocardiogram predicts long-term prognosis in patients with cardiac sarcoidosis

Fragmented QRS (fQRS) on a 12-lead electrocardiogram is a known marker of fatal arrhythmias or cardiac adverse events in ischemic and non-ischemic cardiomyopathy patients. Nonetheless, the association between fQRS and clinical outcomes in patients with cardiac sarcoidosis (CS) remains unclear. Herein, we investigated whether fQRS is associated with long-term clinical outcomes in CS patients. A total of 78 patients who received immunosuppressive therapy (IST) for clinically diagnosed CS were retrospectively examined. Patients were classified into two groups according to the presence (n = 19) or absence (n = 59) of fQRS on electrocardiogram before IST. The primary outcome was the composite event of all-cause death, ventricular tachyarrhythmias (VTs), and hospitalization for heart failure. Results of late gadolinium enhancement on cardiac magnetic resonance imaging were also analyzed. During a median follow-up period of 3.7 years (interquartile range: 1.6-6.2 years), the primary outcome occurred more frequently in patients with fQRS than in those without (47% vs. 13%, log-rank p = 0.002). Multivariable Cox regression analyses showed that fQRS was an independent determinant of the primary outcome. The incidence of VTs, within 12 months of IST initiation, was comparable between the two groups; however, late-onset VTs, defined as those occurring ≥ 12 months after IST initiation, occurred more frequently in the fQRS group (21% vs. 2%, log-rank p = 0.002). The scar zone and scar border zone were greater in patients with fQRS than in those without it. In conclusion, our analysis suggests that fQRS is an independent predictor of adverse events, particularly late-onset VTs, in patients with CS.

Fragmented QRS complex on a 12-lead electrocardiogram predicts cardiovascular and all-cause mortality in dialysis patients

BACKGROUND

Cardiovascular disease (CVD) is the most common cause of mortality in end-stage renal disease (ESRD) patients. Fragmented QRS complex (fQRS) has been reported as a helpful marker in evaluating various cardiovascular pathologies. We aimed to investigate the value of the fQRS complex clinical decision of ESRD patients receiving dialysis.

METHODS

This prospective observational study included 411 patients receiving hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) between 2016-01-01 and 2020-12-31. The primary outcomes were all-cause and cardiovascular (CV) mortality.

RESULTS

HD patients have elevated values of fQRS complex compared to CAPD patients (39.1% vs. 28.2%, P = 0.027). Significantly, fQRS complex in the anterior/lateral leads is associated with all-cause and CV mortality stronger than fQRS in the inferior leads (P = 0.008). In a multivariate Cox regression analysis, HD patients with fQRS complex had a higher incidence of all-cause mortality (hazard ratio [HR] = 1.860; 95% confidence interval [CI]: [1.032, 3.349]; p = 0.041) and CV mortality (HR = 2.989; 95% CI [1.357, 6.584]; p = 0.007). For CAPD patients, fQRS complex was also associated with increased risk of all-cause mortality (HR = 1.593; 95% CI [1.023, 2.580]; p = 0.049) and increased risk of CV mortality (HR = 2.392; 95% CI [1.348, 4.173]; p = 0.013).

CONCLUSIONS

The presence of the fQRS complex was an independent predictor of all-cause and CV mortality in HD and CAPD patients. We suggested a potential role of the fQRS complex in CV risk strata for dialysis patients and the choice of dialysis modality.

Fragmented QRS Is Independently Predictive of Long-Term Adverse Clinical Outcomes in Asian Patients Hospitalized for Heart Failure: A Retrospective Cohort Study

Background: Fragmented QRS (fQRS) results from myocardial scarring and predicts cardiovascular mortality and ventricular arrhythmia (VA). We evaluated the prevalence and prognostic value of fQRS in Asian patients hospitalized for heart failure.

Methods and Results: This was a retrospective cohort study of adult patients hospitalized for heart failure between 1st January 2010 and 31st December 2016 at a tertiary center in Hong Kong. The baseline ECG was analyzed. QRS complexes (<120 ms) with fragmented morphology in ≥2 contiguous leads were defined as fQRS. The primary outcome was a composite of cardiovascular mortality, VA, and sudden cardiac death (SCD). The secondary outcomes were the components of the primary outcome, myocardial infarction, and new-onset atrial fibrillation. In total, 2,182 patients were included, of whom 179 (8.20%) had fQRS. The follow-up duration was 5.63 ± 4.09 years. fQRS in any leads was associated with a higher risk of the primary outcome (adjusted hazard ratio (HR) 1.428 [1.097, 1.859], p = 0.001), but not myocardial infarction or new-onset atrial fibrillation. fQRS in >2 contiguous leads was an independent predictor of SCD (HR 2.679 [1.252, 5.729], p = 0.011). In patients without ischaemic heart disease (N = 1,396), fQRS in any leads remained predictive of VA and SCD (adjusted HR 3.526 [1.399, 8.887], p = 0.008, and 1.873 [1.103, 3.181], p = 0.020, respectively), but not cardiovascular mortality (adjusted HR 1.064 [0.671, 1.686], p = 0.792).

Conclusion: fQRS is an independent predictor of cardiovascular mortality, VA, and SCD. Higher fQRS burden increased SCD risk. The implications of fQRS in heart failure patients without ischaemic heart disease require further studies.

Fragmented QRS as a predictor of cardiac events in patients with cardiac sarcoidosis

BACKGROUND

Multiple spikes within the QRS complex, known as fragmented QRS (fQRS), are associated with the occurrences of ventricular arrhythmic events (VAEs) in patients with Brugada syndrome and hypertrophic cardiomyopathy. However, the association between fQRS and occurrence of VAEs in patients with cardiac sarcoidosis (CS) has not been elucidated.

METHODS

We evaluated the associations between fQRS and cardiac events including VAEs [non-sustained ventricular tachycardia (NSVT), sustained ventricular tachycardia (VT), and ventricular fibrillation (VF)], hospitalization for heart failure, and all-cause death in 68 patients with CS (30 patients with fQRS vs. 38 patients without fQRS) over a 5-year period.

RESULTS

Cardiac events occurred in 22 patients with fQRS and 18 patients without fQRS (73% vs. 47%, p=0.009). Of the cardiac events that occurred in CS patients, VAEs occurred more frequently in patients with fQRS than in patients without fQRS (VAEs: 70% vs. 45%, p=0.017; NSVT: 70% vs. 45%, p=0.010; VT: 43% vs. 18%, p=0.011, and VF: 6.7% vs. 2.6%, p=0.34), whereas there was no significant difference in hospitalization for heart failure or all-cause death between patients with and those without fQRS (hospitalization for heart failure: 6.7% vs. 5.3%, p=0.75; all-cause death: 6.7% vs. 5.3%, p=0.64). Multivariate analysis showed that fQRS in the baseline electrocardiogram was independently associated with VAEs (hazard ratio: 2.21, 95% confidence interval: 1.15-4.25, p=0.017).

CONCLUSION

fQRS is a predictor of VAEs in patients with CS.

Fragmented QRS on far-field intracardiac electrograms as a predictor of arrhythmic events

BACKGROUND

Studies suggest that fragmented QRS (fQRS) can predict arrhythmic events in various cardiac diseases. However, the association between fQRS recordings on intracardiac electrogram (EGM) and ventricular arrhythmic events remains unknown.

METHODS

We enrolled 51 patients (age, 62 ± 12 years; 40 men) with an implantable cardioverter-defibrillator (ICD) and structural heart disease and evaluated surface electrocardiogram (ECG) and EGM measurement of fQRS and the association between fQRS and arrhythmic events.

RESULTS

fQRS was detected on surface ECG and ICD-EGM in 12 (23.5%) and 15 (29.4%) patients, respectively. fQRS was detected more frequently on ICD-EGM in patients with fQRS on surface ECG than in patients without fQRS (7/12 [58.3%] vs 8/39 patients [20.5%], P = .01). Appropriate ICD therapies were documented in 16 patients. Among these patients, fQRS was detected more frequently on surface ECG and ICD-EGM in patients with appropriate ICD therapies (8/16, 50.0%; P = .001 and 11/16, 68.9%; P < .001). Nonsustained ventricular tachycardia was significantly more frequent in patients with appropriate ICD therapies (15/16, 93.8%; P = .04). Multiple logistic regression analysis showed that fQRS on ICD-EGM was a predictor of arrhythmic events (P = .03). Kaplan-Meier survival analysis revealed that ICD therapies were significantly more frequent among patients with fQRS on both surface ECG and ICD-EGM than among those without fQRS (66.7% vs 6.6%, P < .001).

CONCLUSION

The presence of fQRS on ICD-EGM can be a predictor of arrhythmic events in ICD patients. Surface ECG and ICD-EGM measurement may help predict ventricular arrhythmic events.

Evaluation of Relationship between fQRS and CD4/CD8 Ratio in Patients with HIV

Objectives:

Myocardial dysfunction is an important cause of morbidity in human immunodeficiency virus (HIV)-infected patients. Decline in CD4 T-cell level and reversal of CD4/CD8 ratio was associated with cardiovascular events. Fragmented QRS (fQRS) can show myocardial dysfunction and cardiovascular events. The aim of this study is to investigate the presence of fQRS in HIV-infected patients and the factors affecting it.

Methods:

This case-control study included 153 outpatient HIV patients (97% male) and 141 healthy subjects (96% male). Patients with cardiac disease history, arrhythmia, diabetes, cancer disease, and thyroid dysfunction were excluded from the study. Electrocardiogram, echocardiography, and biochemistry tests were performed to all participants. CD4 and CD8 T cell count, and HIV RNA level were measured in HIV-infected patients.

Results:

Both groups had similar basal characteristics. Mean CD4 T-cell level was 356 cell/cm3, HIV was under control in 48%, and the rate of antiretroviral treatment use was 64%. HIV-infected patients had lower left ventricular ejection fraction (LVEF), higher Tei index, and more fQRS. HIV-infected patients with fQRS had lower nadir CD4 T-cell levels, lower CD4/CD8 ratio, and higher Tie index. In multivariate analysis, CD4/CD8 ratio and LVEF were found to be independent predictors of fQRS in HIV-infected patients.

Conclusion:

Myocardial dysfunction can be seen in HIV-infected patients. Caution should be exercised in terms of myocardial dysfunction in HIV-infected patients with low CD4/CD8 ratio.

Cardiac Sarcoidosis: Pathophysiology, Diagnosis, and Management

Sarcoidosis is a chronic multi-system disorder with an unknown etiology that can affect the cardiac tissue, resulting in Cardiac Sarcoidosis (CS). The majority of these CS cases are clinically silent, and when there are symptoms, the symptoms are vague and can have a lot in common with other common cardiac diseases. These symptoms can range from arrhythmias to heart failure. If CS goes undetected, it can lead to detrimental outcomes for patients. Diagnosis depends on timely utilization of imaging modalities and non-invasive testing, while in some cases, it does necessitate biopsy. Early diagnosis and treatment with immunosuppressive agents are crucial, and it is essential that follow-up testing be performed to ensure resolution and remission. This manuscript provides an in-depth review of CS and the current literature regarding CS diagnosis and treatment.

Fragmented QRS on surface electrocardiography as a predictor of cardiac mortality in patients with SARS-CoV-2 infection

Aims

Although severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is mainly a respiratory system disease, recent studies reported that cardiac injury is associated with poor outcomes in this population. There are few studies which assessed standard electrocardiogram (ECG) as a prognostic tool during the course of SARS-CoV-2 infection. The aim of this study is to identify the relationship between of ECG parameters and prognosis of patients infected with SARS-CoV-2.

Method and results

A total of 114 consecutive patients with a confirmed diagnosis of SARS-CoV-2 infection between March 2020 and May 2020 were included in the study. Standard 12‑lead surface ECG was reviewed for presence of fragmented QRS (fQRS), abnormal Q wave, T wave inversion, and duration of QRS. fQRS was observed in 36.8% (n = 42) of the patients who had SARS-CoV-2. Patient groups with and without fQRS did not differ in terms of age, gender, the presence of comorbid diseases and medical treatment. Hospitalization duration, intensive care unit(ICU) requirement, all-cause mortality, and cardiac mortality were found to be higher in patients with fQRS (all p values <0.05). There was a positive correlation between QRS duration and duration of hospital stay (p < 0.001, r = 0.421). QRS duration was also found to be associated with intensive care need, all-cause mortality, and cardiac mortality.

Conclusion

Our data shows that QRS duration and the presence of fQRS on standard ECG can help to identify patients with worse clinical outcome admitted for SARS-CoV-2 infection.

Sarcoid Heart Disease: an Update on Diagnosis and Management

PURPOSE OF REVIEW

The purpose of this review is to provide an update on cardiac sarcoidosis (CS) and to discuss the current recommendations and progress in diagnosis and management of this disease. Sarcoidosis is a multisystem granulomatous disease of unknown etiology. Cardiac involvement is seen in at least 25% and is associated with poor prognosis. Manifestations of cardiac sarcoidosis (CS) can vary from presence of silent myocardial granulomas, which may lead to sudden death, to symptomatic conduction abnormalities, ventricular arrhythmias, and heart failure.

RECENT FINDINGS

We discuss newer imaging modalities such as cardiac magnetic resonance imaging and positron emission tomography in conjunction with clinical criteria increasingly used for diagnosing and prognosticating patients with CS. Immunosuppression (primarily corticosteroids) is recommended for treatment of CS; however, its efficacy has never been proven in prospective randomized studies. The role of imaging to guide the use of immunotherapy is unknown. Cardiac sarcoidosis continues to challenge clinicians due to its protean presentations, lack of diagnostic standards, and data for risk stratification and treatment. There is a need for prospective, randomized controlled trials to understand how best to diagnose and treat cardiac sarcoidosis.

The ECG in sarcoidosis - a marker of cardiac involvement? Current evidence and clinical implications

Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by noncaseating granulomas. Cardiac involvement is often limiting patients' prognosis. Cardiac sarcoidosis can manifest with variant cardiac arrhythmias, of which atrioventricular (AV)-block-related bradycardia and ventricular tachycardias are the most common. Although cardiac sarcoidosis remains a histopathological diagnosis, the significance of imaging modalities, especially cardiac magnetic resonance imaging is increasing rapidly but mainly remains reserved for patients with a high suspicion due to a previous arrhythmia or unknown cardiomyopathy. Thus, there is a need for screening in daily clinical practice so that possible characteristic electrocardiographic (ECG) findings may guide the way to detect the disease. We therefore evaluated the ECG as a potential tool for screening of cardiac sarcoidosis and present different electrophysiological manifestations of cardiac sarcoidosis based on a literature review. The ECG is a valuable tool for screening of cardiac involvement in patients with sarcoidosis. Several parameters have been shown to be associated with cardiac involvement in sarcoidosis such as higher-degree AV-block, QRS complex fragmentation and widening, as well as certain T wave abnormalities that may indicate cardiac involvement, of which the latter two are most promising and specific. However, prospective studies examining a large number of trials are desirable.

Fragmented QRS complex in patients with systemic lupus erythematosus at the time of diagnosis and its relationship with disease activity

Objective

Cardiovascular disease is an important contributor to the mortality rate of patients with systemic lupus erythematosus (SLE), which is related to SLE disease activity. Fragmented QRS (fQRS) complexes, defined by additional spikes in the QRS complex, are useful for identifying myocardial scars on electrocardiography and can be an independent predictor of cardiac events. We aimed to assess the relationship between disease activity in patients with SLE and fQRS at the time of diagnosis.

Methods

Forty-four patients with SLE were included. Patients with cardiac diseases, other rheumatic diseases, and prior treatment at the time of electrocardiography measurement were excluded. The appearance of fQRS represented exposure. The primary outcome was SLE Disease Activity Index 2000 (SLEDAI-2K). Multiple regression analysis was conducted to assess the association between fQRS and SLEDAI-2K adjusted for age, sex, and time from the estimated onset date to the date of diagnosis.

Results

Among patients with SLE at diagnosis, 26 (59.1%) had fQRS. The median SLEDAI-2K was 18 (interquartile range [IQR], 12–22) and 9 (IQR, 8–15) in the fQRS(+) and fQRS(-) groups, respectively. SLEDAI-2K was significantly higher in the fQRS(+) group than in the fQRS(-) group (regression coefficient, 2.69; 95% confidence interval, 0.76–4.61; p = 0.008).

Conclusion

Our results suggested that fQRS(+) patients with SLE had high disease activity. fQRS could likely detect subclinical myocardial involvement in patients with SLE and predict long-term occurrence of cardiac events.

Bundle Branch Blocks and Fragmented QRS Complex in Iranian Patients with Systemic Sclerosis

Background: Cardiac involvement, as one of the life-threatening manifestations of systemic sclerosis (SSc), is chiefly caused by collagen fiber deposition in the myocardium, which subsequently leads to conduction abnormalities. In the present study, we aimed to investigate the prevalence and clinical significance of bundle branch blocks (BBBs) and the fragmented QRS complex (fQRS) in Iranian patients with SSc. Methods: Forty-one patients with SSc were enrolled from the outpatient SSc clinic of Shariati Hospital, Tehran University of Medical Sciences, between October 2016 and February 2017. Twelve-lead ECG was obtained and interpreted for BBBs and the fQRS. To adjust for the confounding effects of non-SSc-related cardiovascular risk factors, we calculated the Framingham risk score to estimate the risk of cardiovascular diseases. The associations between the studied conduction abnormalities and SSc cutaneous subtypes; disease duration; and the Medsger SSc severity scale of cutaneous, pulmonary, and vascular involvements were also analyzed. Results: The study population consisted of 41 Iranian patients with SSc at a mean age of 47.48±11.57 years (82.9% female). The prevalence of BBBs and the fQRS was 26.8% and 36.6%, respectively. The fQRS was associated with the limited cutaneous SSc subtype (OR: 0.100, 95%CI: 0.018-0.553, and P=0.028). BBBs and the fQRS were not associated with either the Framingham risk score or the rest of the clinicodemographic variables. Conclusion: BBBs and the fQRS were more prevalent in our patients with SSc, without any association with the involvement of the other organs. These findings may suggest the independent pathophysiology of cardiac involvement in SSc.

Investigation of mindin levels in hypertensive patients with left ventricular hypertrophy and QRS fragmentation on electrocardiography

PURPOSE

Mindin was associated with diabetic nephropathy, podocyte injury, colitis, allergic asthma, liver ischaemia and reperpusion injury and ischaemic brain injury. On the other hand, it was reported as a protective factor against obesity, cardiac hypertrophy, fibrosis and remodelling. Fragmented QRS complexes (fQRS) are markers of altered ventricular depolarisation owing to a prior myocardial scar and fibrosis. In this study, we aimed to investigate mindin levels in hypertensive patients with left ventricular hypertrophy and fQRS on electrocardiography.

METHODS

This observational case-control study enrolled 70 (36 female) hypertensive patients with fQRS and 38 (23 female) hypertensive control patients. All patients were evaluated by transthoracic echocardiography. Mindin levels were measured by the enzyme-linked immunosorbent assay (ELISA). Clinical, echocardiographic and laboratory data were compared between patient and control groups.

RESULTS

There was no significant difference between patient and control groups in terms of clinical, echocardiographic and routine laboratory parameters. The mindin levels were significantly higher in the patient group than controls (11.3 (7.21-19.31) vs 4.15 (2.86-6.34); p < .001). Multiple logistic regression analyses defined increased mindin levels as an independent predictor for the presence of fQRS (Odds ratio: 1.733; p = .034). Mindin levels >6.74 predicted the presence of fQRS with a sensitifity of 84.3% and specificity of 79.9% on receiver operating characteristic (ROC) curve analysis (The area under the curve:0.889; Confidence Interval: 0.827-0.951; p < .001).

CONCLUSION

Mindin expressin is upregulated in hypertensive patients with fQRS complexes. In contrary to previous studies, increased mindin levels may be associated with myocardial fibrosis.

Fragmented QRS on 12-Lead Electrocardiogram Is Correlated With Severe Coronary Artery Disease and Abnormal Myocardial Perfusion Scintigraphy Results in Renal Transplant Candidates

OBJECTIVES

Coronary artery disease is a major cause of mortality and morbidity after renal transplant. Fragmented QRS on standard 12-lead electrocardiograms has been proposed as a marker of myocardial scar, mainly due to coronary artery disease. Here, we aimed to investigate fragmented QRS to detect severe coronary artery disease in renal transplant candidates.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 534 patients with end-stage renal failure who were on the deceased-donor renal transplant wait list at Başkent University Faculty of Medicine due to having no living kidney donor available. We evaluated patients with standard 12-lead electrocardiograms, myocardial perfusion scintigraphy, and coronary angiography. We compared fragmented QRS prevalence versus myocardial perfusion scintigraphy abnormalities and severe coronary artery disease. Correlations among these were analyzed.

RESULTS

Of 92 renal transplant candidates (median age of 56.5 y; range, 24-80 y), 87 patients (94.6%) had myocardial perfusion defects and 72 (78.3%) had myocardial wall motion abnormalities on myocardial perfusion scintigraphy. Forty-four patients (47.8%) had severe coronary artery disease on coronary angiography, and 51 patients (55.4%) had fragmented QRS. Fragmented QRS was significantly more common among patients with myocardial scar. Coronary artery disease was significantly more common in patients with fragmented QRS (P = .042) and in those with fragmented QRS combined with myocardial perfusion defects (P < .01). Fragmented QRS was significantly correlated with presence of myocardial scar and any perfusion defects. When combined with myocardial perfusion defects, fragmented QRS was significantly correlated with severe coronary artery disease (P < .05).

CONCLUSIONS

Fragmented QRS was significantly correlated with abnormal myocardial perfusion scintigraphy and severe coronary artery disease in renal transplant candidates. This simple parameter can provide valuable information on severe coronary artery disease and help to prevent excess patient morbidity and mortality from this disease after renal transplant.

A complete heart block in a young male: a case report and review of literature of cardiac sarcoidosis

Cardiac sarcoidosis is one of the uncommon causes of heart failure. Generally, it presents in the form of varying clinical manifestations ranging from asymptomatic to fatal arrhythmias such as ventricular tachycardia and complete heart block. It is difficult to make a diagnosis strictly based on clinical grounds. However, in the setting of extracardiac sarcoidosis and patients presenting with advanced heart block or ventricular arrhythmia, direct cardiac involvement should be suspected. The definitive diagnosis of cardiac sarcoidosis can be made from endomyocardial biopsy, but it is falling out of favor due to patchy myocardial involvement, considerable procedure-related risks, and advancement in additional imaging modalities. Once cardiac sarcoidosis has been diagnosed, management of the disease remains challenging. Steroids are considered the mainstay of therapy, and implantable cardioverter defibrillator therapy can be considered in a selected group of patients at greater risk for malignant ventricular arrhythmias.

Relationship Between Fragmented QRS Complexes and Cardiac Status in Duchenne Muscular Dystrophy: Multimodal Validation Using Echocardiography, Magnetic Resonance Imaging, and Holter Monitoring

The presence of fragmented QRS is a known marker of heterogeneous ventricular activation around the myocardial scar area. We validated whether fragmented QRS shows any association with ventricular dysfunction, fibrosis, or ventricular arrhythmias in patients with Duchenne muscular dystrophy (DMD). Thirty-seven patients with DMD were evaluated using electrocardiography (ECG), echocardiography, cardiac magnetic resonance, and 24-h Holter monitoring. Associations between fragmented QRS and ventricular dysfunction, fibrosis, or ventricular arrhythmia were investigated. Fragmented QRS complexes were present in 31 of 37 (83.7%) patients, and they were associated with a significantly lower left ventricular ejection fraction along with an increased left ventricular Tei index as evaluated by echocardiography, and more frequent ventricular arrhythmia as indicated using 24-hour Holter monitoring compared with patients without fragmented QRS. The number of leads with fragmented QRS correlated negatively with left ventricular ejection fraction both using echocardiography (r = -0.616) and CMR (r = -0.516). Further, the number of leads with fragmented QRS showed a significant correlation with several other echocardiographic measurements (mitral Em and Sm, and left ventricular Tei index), and 2-dimensional speckle-tracking echocardiography derived global left ventricular longitudinal strain. The frequency of ventricular arrhythmia observed using Holter monitoring showed a significant positive correlation with the frequency of fragmented QRS on ECG (r = 0.674). There was a positive trend of correlation between fragmented QRS and the amount of myocardial fibrosis as assessed by late gadolinium enhancement using CMR, but the statistical significance of the relationship was low (r = 0.433, p = 0.056). Fragmentation of QRS complexes is associated with degrees of left ventricular dysfunction, fibrosis, and ventricular arrhythmias in patients with DMD.

QRS Fragmentation Patterns Representing Myocardial Scar Need to Be Separated from Benign Normal Variants: Hypotheses and Proposal for Morphology based Classification

The presence of a fragmented QRS complex (fQRS) in two contiguous leads of a standard 12-lead electrocardiogram (ECG) has been shown to be an indicator of myocardial scar in multiple different populations of cardiac patients. QRS fragmentation is also a predictor of adverse prognosis in acute myocardial infarction, coronary artery disease, and ischemic cardiomyopathy and a prognostic tool in structural heart diseases. An increased risk of sudden cardiac death associated with fQRS has been documented in patients with ischemic cardiomyopathy and hypertrophic cardiomyopathy. However, fQRS is also frequently observed in apparently healthy subjects. Thus, a more detailed classification of different QRS fragmentations is needed to identify the pathological fragmentation patterns and refine the role of fQRS as a risk marker of adverse cardiac events and sudden cardiac death. In most studies fQRS has been defined by the presence of an additional R wave (R′), or notching in the nadir of the S wave, or the presence of >1 R′ in two contiguous leads corresponding to a major coronary territory. However, this approach does not discriminate between minor and major fragmentations and the location of the fQRS is also neglected. In addition to this, the method is susceptible to large interobserver variability. We suppose that some fQRS subtypes result from conduction delays in the His-Purkinje system, which is a benign finding and thus can weaken the prognostic values of fQRS. The classification of fQRSs to subtypes with unambiguous definitions is needed to overcome the interobserver variability related issues and to separate fQRSs caused by myocardial scarring from benign normal variants. In this paper, we review the anatomic correlates of fQRS and the current knowledge of prognostic significance of fQRS. We also propose a detailed fQRS classification for research purposes which can later be simplified after the truly pathological morphologies have been identified. The research material of our study consist of 15,245 ECGs from the random general population and approximately six thousands (n = 6,241) ECGs from subjects with a known cardiac disease.

[Fragmented QRS. Relevance in clinical practice]

The QRS complex represents the electrical depolarization of ventricular myocardium. In the case of an undisturbed depolarization, the QRS complex has a normal configuration and duration, but abnormal electrical conduction leads to widening of the QRS complex. The block of one of the Tawara branches results in a typical bundle branch block pattern. A QRS complex that cannot be classified as bundle branch block due to an atypical configuration and contains notched R or S waves is called a fragmented QRS. The underlying pathophysiologies are manifold and include myocardial scars induced by ischemic heart disease, myocardial fibrosis due to other diseases, primary cardiac pathologies as well as systemic diseases with cardiac involvement. Pathologies on the cellular level, such as ion channel dysfunctions, also correlate with fragmented QRS. Besides the diagnostic relevance, fragmented QRS is known to have prognostic properties, for example in identifying high risk patients with coronary artery disease, cardiomyopathy, Brugada syndrome and acquired long QT syndrome; however, fragmented QRS may also be detected in ECGs of healthy individuals.

Mid-ventricular Hypertrophic Obstructive Cardiomyopathy with Apical Aneurysm Complicated with Syncope by Sustained Monomorphic Ventricular Tachycardia

Mid-ventricular hypertrophic obstructive cardiomyopathy with secondary formation of apical aneurysm is a rare variant of hypertrophic cardiomyopathy. They have a unique behavior because unlike other variants it causes sustained monomorphic ventricular tachycardia, which makes it particularly severe.

Fragmented QRS frequency in patients with cardiac syndrome X

Objective:

Cardiac syndrome X (CSX) is characterised by typical exertional chest pain, a positive response to exercise testing, and a normal coronary angiography. The relationship of CSX with myocardial fibrosis and ischemia has been clearly demonstrated in previous studies. In addition, fragmented QRS (fQRS) has been reported in the literature as an indicator of myocardial fibrosis. The aim of this study was to investigate the frequency of fQRS in patients with CSX.

Methods:

This prospective case-control study included 37 patients (CSX group) with typical complaints of angina, ischemia on an exercise test, and normal coronary arteries as detected by angiography and 47 patients (control group) with normal coronary arteries. Echocardiographic examinations were performed according to the recommendations of the American Society of Echocardiography. Continuous variables were expressed as mean±standard deviation (SD), and the qualitative variables were expressed as a percentage or ratio. Data were compared statistically with Shapiro–Wilk test, Student’s t-test, Mann-Whitney U, chi-square and Fisher exact test.

Results:

There was no significant difference between the CRX and control groups with respect to basic characteristics such as age and sex. fQRS and the frequency of its presentation with stable angina pectoris at the clinic were significantly higher in the CSX group than in the control group (p values: 0.001 and <0.001, respectively).

Conclusion:

A close follow-up would be useful in CSX patients in whom fQRS is detected in an electrocardiogram (ECG) because of the association between fQRS and poor prognosis with respect to the prevention of late complications. We believe that the presence of fQRS in the ECG aids in the diagnosis of CSX in clinical practice and in the recognition of this group of patients. (Anatol J Cardiol 2016; 16: 616-20)

Methodology for automated detection of fragmentation in QRS complex of Standard 12-lead ECG

Fragmented QRS (f-QRS) has been found to have higher sensitivity and/or specificity values for several diseases including remote and acute myocardial infarction, cardiac sarcoidosis etc, compared to other conventional bio-markers viz. Q-wave, ST-elevation etc. Several of these diseases do not have a reliable bio-marker and hence, patients suffering from them have to undergo expensive and sometimes invasive tests for diagnosis viz. myocardial biopsy, cardiac catheterization etc. This paper proposes automation of fragmentation detection which will lead to a more reliable diagnosis and therapy reducing human error, time consumption and thereby alleviating the need of enormous training required for detection of fragmentation. In this paper, we propose a novel approach to detect the discontinuities present in QRS complex of standard 12-lead ECG, known as fragmented QRS, using Discrete Wavelet transform (DWT) targeting both hospital-based and remote health monitoring environments. Fragmentation Detection Algorithm (FDA) was designed and modeled using PhysioNet's PTBDB and upon reiterative refinements it successfully detected all discontinuities in the QRS complex. The QRS complexes of 31 patients obtained randomly from PhysioNet's PTBDB were examined by two experienced cardiologists and the measurements obtained were compared with the results of our proposed FDA leading to 89.8% agreement among them.

Radiotherapy Induces Development of Fragmented QRS in Patients with Breast Cancer

BACKGROUND

Myocardial fibrosis is a well-known side effect of radiotherapy. Fragmented QRS (fQRS) has been shown to be a marker of myocardial fibrosis. We postulated that radiotherapy induces development of fQRS in breast cancer patients.

PATIENTS AND METHODS

Breast cancer patients receiving locoregional radiotherapy were enrolled. Patients who had fQRS on electrocardiography (ECG) before radiotherapy were excluded. All patients were revaluated for the development of fQRS at 1-year follow-up. An age-matched healthy group served as controls.

RESULTS

A total of 52 breast cancer patients receiving locoregional radiotherapy were included (median age 49 years, interquartile range (IQR) 13). Of these, 19 (37%) had developed fQRS at 1-year follow-up. Compared with the control group, prevalence of fQRS was significantly higher in the irradiated group (37 vs. 12%; p < 0.002). Median total cardiac radiation dose was significantly higher in patients who had developed fQRS (5 Gy, IQR 5.2 vs. 1.7 Gy, IQR 4.4; p = 0.003). Cardiac radiation dose, entered either as a continuous variable (odds ratio (OR) 1.35, 95% confidence interval (CI) 104-1.74) or as a dichotomized variable (≥ 2.2 Gy, OR 6.48, 95% CI 1.47-28.61), was independently associated with the development of fQRS at 1-year follow-up.

CONCLUSION

Radiotherapy for breast cancer induces development of fQRS on ECG. Cardiac radiation dose is independently associated with the development of fQRS.

fQRS as a marker of granulomatous disease in patients presenting with ventricular tachycardia and normal left ventricular ejection fraction

BACKGROUND

Granulomatous myocarditis may present with sustained monomorphic ventricular tachycardia (SMVT) in the presence of normal left ventricular ejection fraction (LVEF), and could be mistaken for idiopathic ventricular tachycardia (IVT). The use of cardiac imaging for diagnosis can be limited by availability and high cost. ECG is readily available and inexpensive. Fragmented QRS (fQRS) on ECG has been found to be associated with myocardial scar. We hypothesized that fQRS could be useful in the diagnosis of granulomatous VT (GVT).

METHODS

We compared the 12-lead ECG of 16 patients with GVT and 42 patients with IVT who presented with SMVT.

RESULTS

The presence of fQRS was significantly higher in the GVT group compared to the IVT group (75% versus 19.1%, p < 0.001). The location of fQRS correlated with delayed enhancement cardiac magnetic resonance imaging (DE-CMR) in the same segment in 4/16 patients in the GVT group. It correlated with an affected segment on either DE-CMR or 18FDG positron emission computed tomography in 4/11 patients in the GVT group who had both imaging modality. Whenever fQRS was present in contiguous leads other than the inferior leads, it always corresponded to an affected segment on imaging.

CONCLUSIONS

In patients presenting with SMVT and no structural heart disease, the presence of fQRS is strongly associated with granulomatous myocarditis. fQRS on the surface ECG is a helpful tool the presence of which should prompt a CMR for a definitive diagnosis.

Usefulness of notched duration to predict response to cardiac resynchronization therapy

OBJECTIVES

The presence of notches in the biventricular paced QRS complex (BiP-QRS) from the posterolateral cardiac vein displays delays in the activation of the left ventricle and may consequently be linked with longer times of stimulus conduction. Our objective was to determine the relationship between the notch duration ≥ 0.1 mV in the BiP-QRS and the effectiveness of cardiac resynchronization therapy (CRT).

DESIGN

A total of 210 patients, who underwent de novo CRT implantation previously and had ≥ 1 follow-up between August 2009 and February 2014, were enrolled in the study. Echocardiographic response to CRT was defined as "an increase of ≥ 5% in ejection fraction" and clinical response to CRT was defined as "an improvement ≥ 1 in New York Heart Association class without heart failure hospitalization after 6 months of CRT implantation."

RESULTS

At a mean follow-up of 9.2 ± 2.1 months, 142 patients (67%) were classified as responders to CRT. BiP-QRS duration was significantly longer among non-responders compared with responders (p = 0.036). More of the non-responders have notched in their BiP-QRS than responders (63% vs. 40%, p = 0.002). Median duration of notch was significantly higher among non-responders (80 ms vs. 67.5 ms, p = 0.041). Notch duration > 67.5 ms was associated with 2.8 times higher non-response to therapy (odds ratio: 2.8; 95% confidence interval: 1.075-7.588, p = 0.035).

CONCLUSIONS

Patients with notch duration greater than 67.5 ms are associated with poor response to CRT. Notch duration > 67.5 ms predicts non-response to therapy with 50.0% specificity and 72.1% sensitivity.

Pathophysiology and clinical management of cardiac sarcoidosis

Cardiac sarcoidosis is a potentially life-threatening condition characterized by formation of granulomas in the heart, resulting in conduction disturbances, atrial and ventricular arrhythmias, and ventricular dysfunction. The presentation of cardiac sarcoidosis ranges from asymptomatic with an abnormal imaging scan, to palpitations, syncope, symptoms of congestive heart failure, and sudden cardiac death. Screening for cardiac sarcoidosis has not been standardized, but the presence of cardiac symptoms on medical history and physical examination, and an abnormal electrocardiogram (ECG), Holter monitoring, or echocardiogram has been shown to be highly sensitive for detecting cardiac sarcoidosis. A signal-averaged ECG might also have a role in screening for cardiac sarcoidosis in asymptomatic patients. Although endomyocardial biopsies are highly specific for the diagnosis of cardiac sarcoidosis, procedural yield is very low and appropriate findings on cardiac MRI or PET are, therefore, often used as diagnostic surrogates. Treatment for cardiac sarcoidosis usually involves immunosuppressive therapy, particularly corticosteroids. Additional therapy might be required, depending on the clinical presentation, including implantation of an internal defibrillator, antiarrhythmic agents, and catheter ablation.

Association of Fragmented QRS with Subclinical Left Ventricular Dysfunction in Patients with Obstructive Sleep Apnea

OBJECTIVE

We aimed to investigate whether fragmented QRS (fQRS) is associated with subclinical left ventricular (LV) dysfunction in patients with obstructive sleep apnea (OSA).

SUBJECTS AND METHODS

A total of 141 patients with OSA who had normal LV ejection fraction (LVEF) were included in the study. The fQRS was defined as the presence of an additional R wave, notching of R or S wave or the presence of fragmentation in 2 contiguous electrocardiography (ECG) leads. Subclinical LV dysfunction was defined as the presence of a tissue Doppler-derived Tei index of ≥ 0.5 in the absence of impaired LVEF (<50%) as assessed by transthoracic echocardiography.

RESULTS

Of the 141 patients, 71 (50.4%) had subclinical LV dysfunction. Overall, the prevalence of the fQRS was 61% (86/141). Patients with fQRS had significantly higher Tei indices than those without fQRS [median 0.66, interquartile range (IQR) 0.39 vs. median 0.40, IQR 0.15, p < 0.001]. The presence of fQRS on ECG predicted subclinical LV dysfunction in univariate logistic regression analysis [odds ratio (OR) 6.69, 95% confidence interval (CI) 3.10-14.43]. The association remained significant after adjusting for all potential confounders (OR 4.59, 95% CI 1.94-10.87).

CONCLUSION

fQRS on ECG was an independent predictor of subclinical LV dysfunction in patients with OSA. This simple tool might help to identify OSA patients who could be at risk for developing overt cardiac dysfunction.

Fragmented ECG as a risk marker in cardiovascular diseases

Various noninvasive tests for risk stratification of sudden cardiac death (SCD) were studied, mostly in the context of structural heart disease such as coronary artery disease (CAD), cardiomyopathy and heart failure but have low positive predictive value for SCD. Fragmented QRS complexes (fQRS) on a 12-lead ECG is a marker of depolarization abnormality. fQRS include presence of various morphologies of the QRS wave with or without a Q wave and includes the presence of an additional R wave (R’) or notching in the nadir of the R’ (fragmentation) in two contiguous leads, corresponding to a major coronary artery territory. fQRS represents conduction delay from inhomogeneous activation of the ventricles due to myocardial scar. It has a high predictive value for myocardial scar and mortality in patients CAD. fQRS also predicts arrhythmic events and mortality in patients with implantable cardioverter defibrillator. It also signifies poor prognosis in patients with nonischemic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and Brugada syndrome. However, fQRS is a nonspecific finding and its diagnostic prognostic should only be interpreted in the presence of pertinent clinical evidence and type of myocardial involvement (structural vs. structurally normal heart).

Fragmented QRS predicts the arrhythmic events in patients with heart failure undergoing ICD implantation for primary prophylaxis: more fragments more appropriate ICD shocks

BACKGROUND

Fragmented QRS complex (fQRS) is associated with cardiovascular outcomes in various patient populations. Although there were clinical studies investigating the association of fQRS with arrhythmic events in patients with systolic heart failure, the results were conflicting regarding the association of implantable cardioverter defibrillator (ICD) shocks and fQRS. In this study, we aimed to evaluate the association between the presence and extent of fQRS with appropriate ICD shocks and/or all-cause mortality.

METHODS

A total of 215 patients (age: 58.2 ± 11.6 years, 72.5 % male) with the diagnosis of left ventricular systolic heart failure in whom ICD had been implanted for primary prophylaxis were enrolled. Standard ECG evaluation revealed fQRS complex in 123 patients (57.2 %). The phenomenon of fQRS was defined as deflections at the beginning of the QRS complex, on top of the R wave, or in the nadir of the S wave similar to the definition in CAD.

RESULTS

At mean 23.5 ± 12.1 months follow-up, all-cause mortality was observed in 45 (20.9 %) patients and 111 (51.6 %) patients experienced appropriate ICD shocks. Median number of ECG leads with fQRS were higher in patients with appropriate ICD shocks (3 [2-6] vs 1 [0-2], P < 0.001, respectively). The presence of fQRS (HR: 6.64, 95 % CI: 3.54-12.4, P < 0.001) and the number of leads with fQRS (HR: 1.35, 95% CI: 1.22-1.67) were found as independent predictors of appropriate ICD shocks. Additionally, there was a negative correlation between left ventricular ejection fraction and the number of leads with fQRS (r = -0.434, P < 0.001). Rates of all-cause mortality did not differ between the fQRS(+) (29 [24 % ]) and fQRS(-) (16 [17 % ]) groups (P = 0.27).

CONCLUSION

Our findings suggest that the presence and extent of fQRS complex on standard 12-lead ECG predicts appropriate ICD shocks in patients with left ventricular systolic heart failure who underwent ICD implantation for primary prophylaxis.

Myocardial tissue perfusion predicts the evolution of fragmented QRS in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Fragmented QRS complex (fQRS) is associated with worse outcomes in several cardiovascular conditions. However, alterations in fQRS in patients with ST elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) and association of fQRS with myocardial blush grade (MBG) has not been investigated until now. In this study, we aimed to investigate the association of MBG after primary PCI with evolution of fQRS.

METHODS

Our study consisted of 401 consecutive patients with STEMI who underwent primary PCI. Patients were categorized into two subgroups according to persistence or new-onset of fQRS (Group 1) and absence or resolution of fQRS (Group 2) at 48 hours after primary PCI. The evolution of fQRS on pre- and post-PCI ECG and their relation with myocardial reperfusion parameters were investigated.

RESULTS

Patients in group 1 showed older age, higher rate of smoking, lower HDL-cholesterol, lower LVEF, higher angina-to-door time, higher TIMI frame count, and high rate of patients with MBG <3 compared to patients with group 2 (P < 0.05). In correlation analysis, LVEF showed positive correlation with MBG (r = 0.448, P < 0.001) and negative correlation with the number of leads with fQRS (r = -0.335, P < 0.001). In multivariate regression analysis, new-onset or persistance of fQRS after primary PCI is significantly associated with MBG <3, peak CK-MB level, pre-PCI fQRS at anterior localization and smoking.

CONCLUSION

Our findings showed that despite complete ST-segment resolution in all patients, fQRS is independently associated with impaired microvascular myocardial perfusion. So, fQRS, as a simple and easily available noninvasive marker, may be useful in stratification of high-risk patients with increased extent of infarcted myocardium who underwent primary PCI.

J wave and fragmented QRS formation during the hyperacute phase in Takotsubo cardiomyopathy

BACKGROUND

 The J wave and fragmented QRS (fQRS) on electrocardiography are suggested to be closely related to cardiac arrhythmogenesis. Takotsubo cardiomyopathy (TTC) occasionally causes fatal cardiac conditions including life-threatening ventricular arrhythmia. There has been, however, only 1 case report describing the J wave in TTC, and fQRS has not been reported thus far in relation to clinical courses and prognosis.

METHODS AND RESULTS

 J wave and fQRS formation were investigated in 31 consecutive patients with TTC. Nine patients (29%) had J waves and/or fQRS (group A), whereas the remaining 22 did not (group B). The J wave (4 patients), fQRS (4 patients), or both (1 patient) appeared transiently during the hyperacute phase. Left ventricular ejection fraction was significantly lower in group A. Summed defect score of single-photon emission computed tomography using iodine 123 beta-methyl-p-iodophenyl-pentadecanoic acid, and creatine kinase MB isozyme (CKMB) were significantly higher in group A. On multivariate analysis CKMB was a significant indicator of J wave or fQRS. Moreover, the J wave was a significant indicator for cardiac death and/or ventricular tachyarrhythmia (odds ratio, 11.5; P=0.026).

CONCLUSIONS

 Patients with TTC frequently had J waves and/or fQRS during the hyperacute phase, and which were associated with myocardial damage. J wave was also an indicator for cardiac death and/or ventricular tachyarrhythmia. J waves and fQRS may be useful markers for myocardial damage. 

An automated algorithm for online detection of fragmented QRS and identification of its various morphologies

Fragmented QRS (f-QRS) has been proven to be an efficient biomarker for several diseases, including remote and acute myocardial infarction, cardiac sarcoidosis, non-ischaemic cardiomyopathy, etc. It has also been shown to have higher sensitivity and/or specificity values than the conventional markers (e.g. Q-wave, ST-elevation, etc.) which may even regress or disappear with time. Patients with such diseases have to undergo expensive and sometimes invasive tests for diagnosis. Automated detection of f-QRS followed by identification of its various morphologies in addition to the conventional ECG feature (e.g. P, QRS, T amplitude and duration, etc.) extraction will lead to a more reliable diagnosis, therapy and disease prognosis than the state-of-the-art approaches and thereby will be of significant clinical importance for both hospital-based and emerging remote health monitoring environments as well as for implanted ICD devices. An automated algorithm for detection of f-QRS from the ECG and identification of its various morphologies is proposed in this work which, to the best of our knowledge, is the first work of its kind. Using our recently proposed time-domain morphology and gradient-based ECG feature extraction algorithm, the QRS complex is extracted and discrete wavelet transform (DWT) with one level of decomposition, using the 'Haar' wavelet, is applied on it to detect the presence of fragmentation. Detailed DWT coefficients were observed to hypothesize the postulates of detection of all types of morphologies as reported in the literature. To model and verify the algorithm, PhysioNet's PTB database was used. Forty patients were randomly selected from the database and their ECG were examined by two experienced cardiologists and the results were compared with those obtained from the algorithm. Out of 40 patients, 31 were considered appropriate for comparison by two cardiologists, and it is shown that 334 out of 372 (89.8%) leads from the chosen 31 patients complied favourably with our proposed algorithm. The sensitivity and specificity values obtained for the detection of f-QRS were 0.897 and 0.899, respectively. Automation will speed up the detection of fragmentation, reducing the human error involved and will allow it to be implemented for hospital-based remote monitoring and ICD devices.

Comparison of fragmented QRS and myocardial perfusion-gated SPECT findings

AIM

Fragmented QRS (fQRS) complex is an ECG parameter that has recently been introduced and investigated. It is assumed that fQRS occurs because of disruptions in ventricular conduction due to ventricular infarction and ischemia. Therefore, in this article, we aimed to investigate the relationship between the detection of infarction and ischemia on myocardial perfusion-gated single-photon emission computed tomography images and appearance of fQRS on ECG.

MATERIALS AND METHODS

We retrospectively reviewed the records of patients with a diagnosis of coronary artery disease who were referred to our institution for myocardial perfusion scintigraphy. In total, 261 patients (122 women and 139 men, with a mean age of 61±10.33 years) with and without fQRS (136 and 125, respectively) were included in the present study. The myocardial perfusion scintigraphy results were evaluated for the presence or absence of myocardial ischemia and infarction by visual and quantitative (summed stress score, summed rest, summed difference score, summed motion score, and summed thickening score) assessments. Statistical analysis was performed to determine the relationship between the presence of fQRS and myocardial ischemia and/or infarction. Student's t-test and the Mann-Whitney U-test were used for comparing the results. Pearson's χ2-test and Fisher's exact tests were also used to compare the distribution of variables between the two groups.

RESULTS

The prevalence of ischemia and infarction were found to be, respectively, 4.38-fold and 5.95-fold higher in patients with fQRS compared with the control group. Moreover, the prevalence of both ischemia and infarction was found to be 10.54-fold higher in patients with fQRS compared with the control group.

CONCLUSION

There is a highly statistically significant possibility of detecting ischemia and infarction in perfusion myocardial scintigrams of patients whose ECGs have fQRS.

Fragmented QRS complexes are associated with increased left ventricular mass in patients with essential hypertension

BACKGROUND

Left ventricular hypertrophy (LVH) is an independent predictor of poor prognosis in patients with hypertension. In hypertensive hypertrophy, the pathophysiological mechanism is the accumulation of collagen in the myocardium. Fragmented QRS (fQRS) complexes are associated with myocardial fibrosis.

METHODS

The study population included 90 patients with hypertension and a normal coronary angiogram. The fQRS was defined as the presence of an additional R wave (R'), notching of the R or S wave, or the presence of fragmentation in two contiguous leads corresponding to a major coronary artery. Echocardiographic examinations were performed according to the recommendations of the American Society of Echocardiography.

RESULTS

Forty-five patients who had fQRS and were suitable for the study criteria were compared with 45 age- and gender-matched patients who did not have fQRS according to demographic data and echocardiographic findings. The left ventricular (LV) mass index (g/m(2) ) was significantly higher (P < 0.001) in the group with fQRS. The wall thickness, diameter, volume, and ejection fraction (EF) were higher in this group (P < 0.001). Concentric and eccentric hypertrophy were also higher in this group (P < 0.001). In the logistic regression analysis, fQRS on ECG was an indicator of LVH in hypertensive patients (B = 0.064; P < 0.001; odds ratio = 1.066; 95% confidence interval = 1.041-1.092) CONCLUSION: The LV mass index of the hypertensive patients who had fQRS on their ECGs was significantly higher than that of the patients who did not, and fQRS on ECG was an important indicator of LVH in hypertensive patients.