Fragmented QRS as a predictor of arrhythmic events in patients with hypertrophic obstructive cardiomyopathy. J Interv Card Electrophysiol. 2013;38:159-165. [PMID: 24013705 DOI: 10.1007/s10840-013-9829-z]

Fragmented QRS as a predictor of hypertensive crisis in patients with newly diagnosed essential hypertension: 4-year follow-up data

BACKGROUND

Hypertensive crisis (HC) is a life-threatening condition in patients with hypertension (HT). However, there is no electrocardiography (ECG) marker that can predict which hypertensive patient may develop HC. The fragmented QRS (fQRS) complex is an important prognostic marker in ECG that might be predict cardiovascular events and mortality. Our study aimed to investigate whether fQRS can predict the development of HC in patients with HT, within 4 years of follow-up.

METHODS

Newly diagnosed patients with essential HT were recruited for the study from an outpatient clinic. The patients were divided into two groups according to the presence of HC: HC (+) and HC (-). During follow-up, the relationship between fQRS and HC was evaluated.

RESULTS

The study group included 504 patients with newly diagnosed HT. During the follow-up period, HC occurred in 98 of the patients. In 57 (11.30%) patients, fQRS was observed on ECG; fQRS was detected in the ECG of 19 (19.38%) of the HC (+) patients (p = 0.008). The results of multivariate logistic regression analysis showed that fQRS (p < 0.001) was as independent predictor for HC development. Kaplan-Meier analysis further demonstrated that the presence of fQRS affects the development of hypertensive urgency in hypertensive patients (log-rank p < 0.001).

CONCLUSION

In patients with newly diagnosed HT, the presence of fQRS was found to be an independent predictor of HC.

Arrhythmic Risk Stratification among Patients with Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a cardiac muscle disorder characterized by generally asymmetric abnormal hypertrophy of the left ventricle without abnormal loading conditions (such as hypertension or valvular heart disease) accounting for the left ventricular wall thickness or mass. The incidence of sudden cardiac death (SCD) in HCM patients is about 1% yearly in adults, but it is far higher in adolescence. HCM is the most frequent cause of death in athletes in the Unites States of America. HCM is an autosomal-dominant genetic cardiomyopathy, and mutations in the genes encoding sarcomeric proteins are identified in 30-60% of cases. The presence of this genetic mutation carries more than 2-fold increased risk for all outcomes, including ventricular arrhythmias. Genetic and myocardial substrate, including fibrosis and intraventricular dispersion of conduction, ventricular hypertrophy and microvascular ischemia, increased myofilament calcium sensitivity and abnormal calcium handling, all play a role as arrhythmogenic determinants. Cardiac imaging studies provide important information for risk stratification. Transthoracic echocardiography can be helpful to evaluate left ventricular (LV) wall thickness, LV outflow-tract gradient and left atrial size. Additionally, cardiac magnetic resonance can evaluate the prevalence of late gadolinium enhancement, which when higher than 15% of LV mass is a prognostic maker of SCD. Age, family history of SCD, syncope and non-sustained ventricular tachycardia at Holter ECG have also been validated as independent prognostic markers of SCD. Arrhythmic risk stratification in HCM requires careful evaluation of several clinical aspects. Symptoms combined with electrocardiogram, cardiac imaging tools and genetic counselling are the modern cornerstone for proper risk stratification.

Diagnostic and prognostic electrocardiographic features in patients with hypertrophic cardiomyopathy

The standard 12-lead electrocardiogram (ECG) represents a cornerstone for the diagnosis and evaluation of hypertrophic cardiomyopathy (HCM), the most common genetically determined heart muscle disease, due to its cost-effectiveness and wide availability. The ECG may surprisingly look normal in 4-6% of adult patients, and in less than 3% of paediatric patients, but it is abnormal in the vast majority of the remaining patients. 'Specific' features comprise pathological Q-waves, deep S-waves in V1-V3, or high R-waves in V4-V6 due to left ventricular hypertrophy with T-wave (TW) depression or negative TWs. Negative giant TWs are often found in apical HCM. However, in many patients, the ECG may only show non-specific ST-T changes with diphasic or flat TWs. An isolated inverted TW in lateral leads (usually aVL) may be the only marker for HCM in some patients. Electrocardiogram helps to diagnose sarcomeric HCM and distinguish it from different phenocopies, such as cardiac amyloidosis, glycogen storage, or Fabry disease. Electrocardiogram may also have a prognostic role, identifying high-risk features that could impact the clinical outcome.

Validation of CalECG software for primary prevention heart failure patients: Reducing inter-observer measurement variability

BACKGROUND

In primary prevention heart failure patients the 12‑lead electrocardiogram (ECG) may be useful for the prediction of ventricular arrhythmias. However, inter-observer measurement variability first needs to be identified and any software used, validated.

OBJECTIVE

To compare manual ECG measures with CalECG software and to assess the reliability of visual recognition of fragmented QRS (fQRS) by advanced cardiology trainees.

METHODS

30 pre-implant ECGs were assessed on patients who met guidelines for primary prevention Implantable Cardiac Defibrillator. Parameters included RR, PR, QT, QRS duration, axis location, fQRS and T wave peak to T wave end (TpTe). ECGs were analyzed by members of the cardiology department with different levels of experience, and compared to CalECG software. Interobserver agreement was assessed using Fleiss' Kappa (κ) and intraclass correlation coefficients (ICC). Pearson correlation coefficient (r) was used to compare human and software measures.

RESULTS

Strong/very strong correlation was recorded across manual ECG measures (ICC = 0.749-0.979, p ≤ 0.0001) with moderate/strong correlation for TpTe (ICC = 0.547-0.765, p ≤ 0.001). Advanced cardiology trainees demonstrated substantial agreement on ECG interpretation (κ = 0.788, p ≤ 0.0001), however, reliability of fQRS assessment was only moderate for identification (κ = 0.5, p ≤ 0.0001) and fair for location (κ = 0.295, p = 0.001). CalECG software showed strong/very strong correlation with manual measurement for standard measures (r = 0.756-0.977, p ≤ 0.001). Concordance between human and software TpTe measurements varied between leads, with V5 showing a non-significant weak correlation (r = 0.197).

CONCLUSION

CalECG software showed strong/very strong correlation with standard manual measures which affirms its use in ECG analysis. Advanced cardiology trainees showed greater variability in the identification and location of fQRS.

Electrocardiography clues in assessment of patients with premature ventricular contractions

Background/aim

Some electrocardiography (ECG) parameters such as Tp-e interval, Tp-e / QT ratio, fragmented QRS (fQRS), and heart rate variability (HRV) are related to cardiovascular mortality and morbidity. We aim to investigate the relation between premature ventricular contraction burden and these parameters on 24-h ECG recording.

Materials and methods

The study is a retrospective investigation of the 24-h Holter ECG and echocardiography of 199 patients who underwent the procedures due to complaints of palpitation. A frequency of < 10% PVCs / 24 h was classified as seldom group (98 patients), while > 10% PVCs / 24 h was designated as frequent group (101 patients).

Results

Tp-e interval was significantly longer (62 [54–78] vs 75 [60–84], p < 0.001), Tp-e / QT ratio was significantly increased (0.18 [0.16–0.20] vs 0.21 [0.18–0.22], p = 0.001) in frequent PVC group. The percentage of fQRS was significantly increased in frequent PVC group (30.6% vs 47.5%, p = 0.015). When the groups were compared, no significant difference was found in HRV time domain indices. Positive correlations were observed between PVC burden and Tp-e (r = 0.304, p < 0.001), Tp-e / QT (r = 0.275, p < 0.001).

Conclusion

Our study showed that Tp-e interval, Tp-e / QT and fQRS are associated with frequency of PVCs. These measurements in patients with PVCs may form part of assessment of cardiovascular risk.

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.

Deciphering hypertrophic cardiomyopathy with electrocardiography

The comprehensive assessment of patients with hypertrophic cardiomyopathy is a complex process, with each step concurrently focusing on confirmation of the diagnosis, differentiation between sarcomeric and non-sarcomeric disease (phenocopy), and prognostication. Novel modalities such as genetic testing and advanced imaging have allowed for substantial advancements in the understanding of this condition and facilitate patient management. However, their availability is at present not universal, and interpretation requires a high level of expertise. In this setting, electrocardiography, a fast and widely available method, still retains a significant role in everyday clinical assessment of this population. In our review, we follow a stepwise approach for the interpretation of each electrocardiographic segment, discussing clinical implications of electrocardiographic patterns in sarcomeric disease, their value in the differential diagnosis from phenocopies, and impact on patient management. Outlining the substantial amount of information to be obtained from a simple tracing, we exhibit how electrocardiography is likely to remain an integral diagnostic tool in the future as well.

Importance of electrocardiographic markers in predicting cardiac events in children

ECG is a common diagnostic tool in medical practice. Sudden cardiac death (SCD) is a rare but devastating event. The most common cause of SCD in the young is a primary arrhythmic event, which is often produced by malignant ventricular arrhythmia. Several electrocardiographic markers for ventricular repolarization and depolarization have been proposed to predict this arrhythmic risk and SCD in children. Although many of these parameters can easily be used in clinical practice, some of them need specific techniques for interpretation. In this review, we summarized the current knowledge regarding the clinical importance and the ability of these ECG parameters to predict adverse cardiac events in the pediatric population.

How are ECG parameters related to cardiac magnetic resonance images? Electrocardiographic predictors of left ventricular hypertrophy and myocardial fibrosis in hypertrophic cardiomyopathy

Background

Structural myocardial changes in hypertrophic cardiomyopathy (HCM) are associated with different abnormalities on electrocardiographs (ECGs). The diagnostic value of the ECG voltage criteria used to screen for left ventricular hypertrophy (LVH) may depend on the presence and degree of myocardial fibrosis. Fibrosis can cause other changes in ECG parameters, such as pathological Q waves, fragmented QRS (fQRS), or repolarization abnormalities.

Methods

We investigated 146 patients with HCM and 35 healthy individuals who underwent cardiac magnetic resonance imaging (CMR; with late gadolinium enhancement [LGE] in HCM patients) and standard 12‐lead ECGs. On the ECG, depolarization and repolarization abnormalities, the Sokolow–Lyon index, the Cornell index, and the Romhilt–Estes score were evaluated. The left ventricular ejection fraction, volumes, and myocardial mass (LVM) were quantified. Myocardial fibrosis was quantified on LGE images.

Results

The sensitivity of the Romhilt–Estes score was the highest (75%), and this hypertrophy criterion had the strongest correlation with the LVM index (p < .0001; r = .41). The amount of fibrosis was negatively correlated with the Cornell index (p = .015; r = −.201) and the Sokolow–Lyon index (p = .005; r = −.23), and the Romhilt–Estes score was independent of fibrosis (p = .757; r = 0.026). fQRS and strain pattern predicted more fibrosis, while the Cornell index was a negative predictor of myocardial fibrosis (p < .0001). Among others, the strain pattern was an independent predictor of the LVM (p < .0001).

Conclusion

The Romhilt–Estes score is the most sensitive ECG criterion for detecting LVH in HCM patients, as myocardial fibrosis does not affect this criterion. The presence of fQRS and strain pattern predicts myocardial fibrosis.

New Appearance of Fragmented QRS as a Predictor of Ventricular Arrhythmic Events in Patients With Hypertrophic Cardiomyopathy

BACKGROUND

Multiple spikes in the QRS complex (fragmented QRS [fQRS]) on 12-lead electrocardiography have been associated with ventricular arrhythmic events (VAEs) in patients with hypertrophic cardiomyopathy (HCM). The aim of this study was to assess the association between new appearances of fQRS and cardiac events in patients with HCM.Methods and Results:The association between baseline fQRS and cardiac events, namely VAEs, heart failure-related hospitalization, and all-cause death, was evaluated retrospectively in 146 HCM patients (46 patients with fQRS, 100 without fQRS). The median follow-up was 5.3 years. Cardiac events occurred in 29 patients with baseline fQRS and 32 patients without baseline fQRS (63% vs. 32%; P<0.001). VAEs occurred in a significantly larger percentage of patients with than without baseline fQRS (54% vs. 23%, respectively; P<0.001). Of the 100 patients without baseline fQRS, 33 had a new appearance of fQRS during the 4.6-year follow-up, whereas 67 did not. VAEs occurred more frequently in the 33 patients with the appearance of fQRS than in those without (42% vs. 13%, respectively; P=0.001). Multivariable analysis showed that the new appearance of fQRS documented before VAEs was associated with VAEs (hazard ratio 4.29, 95% confidence interval 1.81-10.2; P=0.001).

CONCLUSIONS

The new appearance of fQRS was associated with an increased risk of VAEs in HCM patients.

Fragmented QRS as a Marker of Myocardial Fibrosis in Hypertension: a Systematic Review

PURPOSE OF REVIEW

Hypertension cause damage in cardiac structure and induce pathological myocardial fibrosis that leads to hypertensive cardiomyopathy. A narrow fragmented QRS complex (fQRS) is associated with myocardial fibrosis and scar tissue in various cardiovascular diseases. It is also associated with myocardial fibrosis in hypertensive patients even in the absence of any structural heart diseases. This article aimed to demonstrate importance and usefulness of fQRS in hypertensive patients.

RECENT FINDINGS

Current evidence suggest that the frequency of fQRS is significantly higher in hypertensive patients compared to normotensives. Also, fQRS seems to be a predictor of left ventricular hypertrophy, increased systolic blood pressure, non-dipping, deterioration of the left ventricular geometry, and worse systolic and diastolic functions in hypertensive patients. As a simple and easy detectable electrocardiographic finding, fQRS may indicate myocardial fibrosis, uncontrolled blood pressure, and deteriorated cardiac structure in hypertensive patients even in the absence of other structural heart diseases, and may also be useful to predict high-risk hypertensives.

A new proof for the relationship between erectile dysfunction and atherosclerosis: fragmented QRS?

In patients with coronary artery disease (CAD), fragmented QRS (fQRS) is a practical marker of myocardial ischemia evaluated on electrocardiography (ECG).The current study investigated the connection between FQRS and erectile dysfunction (ED), which is commonly accepted as an early sign and independent predictor of CAD. The study consisted of a 190 ED patients; 47 of them having severe, 44 moderate, 49 mild-to-moderate, and 50 mild ED, and a control group of 51 otherwise healthy adult men. None of the participants had a history of cardiac disease. There was a significant difference among the groups in terms of fQRS; severe, moderate, and mild-to-moderate ED groups had significantly higher rates of fQRS presence on ECG (27.5%, 23.5%, and 22.5%, respectively) in comparison with those of mild ED and the control groups (13.7% and 12.7%, respectively) (p < 0.001). In patients presenting with ED complaints, a fQRS finding on a simple ECG recording may serve as a first sign of the presence of CAD. As far as we know, the present study is the first in the literature assessing the possible relationship between ED and fQRS. On the ECG, the existence of fQRS was considered to be connected with ED; thus, including this basic parameter into the clinical decisions for ED patients may initiate an extensive diagnostic approach for their underlying cardiovascular diseases.

Baseline fragmented QRS increases the risk of major arrhythmic events in hypertrophic cardiomyopathy: Systematic review and meta-analysis

BACKGROUND

Fragmented QRS reflects disturbances in the myocardium predisposing the heart to ventricular tachyarrhythmias. Recent studies suggest that fragmented QRS (fQRS) is associated with worse major arrhythmic events in hypertrophic cardiomyopathy (HCM). However, a systematic review and meta-analysis of the literature has not been done. We assessed the association between fQRS and major arrhythmic events in hypertrophic cardiomyopathy by a systematic review of the literature and a meta-analysis.

METHODS

We comprehensively searched the databases of MEDLINE and EMBASE from inception to May 2017. Included studies were published prospective or retrospective cohort studies that compared major arrhythmic events (sustained ventricular tachycardia, sudden cardiac arrest, or sudden cardiac death) in HCM with fQRS versus non-fQRS. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate risk ratios and 95% confidence intervals.

RESULTS

Five studies from January 2013 to May 2017 were included in this meta-analysis involving 673 subjects with HCM (205 fQRS and 468 non-fQRS). Fragmented QRS was associated with major arrhythmic events (pooled risk ratio = 7.29, 95% confidence interval: 4.00-13.29, p < .01, I²  = 0%).

CONCLUSION

Baseline fQRS increased major arrhythmic events up to sevenfold. Our study suggests that fQRS could be an important tool for risk assessment in patients with HCM.

Inter- and intra-observer variability of visual fragmented QRS scoring in ischemic and non-ischemic cardiomyopathy

BACKGROUND

Fragmented QRS (fQRS) on a 12-lead ECG has been linked with adverse outcome. However, the visual scoring of ECGs is prone to inter- and intra-observer variability.

METHODS

Five observers, two experienced and three novel, assessed fQRS in 712 digital ECGs, 100 were re-evaluated to assess intra-observer variability. Fleiss and Cohen's Kappa were calculated and compared between subgroups.

RESULTS

The inter-observer variability for assessing fQRS in all leads combined was substantial with a Kappa of 0.651. Experienced observers only had a better agreement with a Kappa of 0.823. Intra-observer variability ranged from 0.736 to 0.880. In the subgroup with ventricular pacing the inter-observer variability was even significantly larger when compared to ECGs with normal QRS duration (Kappa 0.493 vs 0.664, p<0.001).

CONCLUSION

The visual assessment of QRS fragmentation is prone to inter- and intra-observer variability, mainly influenced by the experience of the observers, the underlying rhythm and QRS morphology.

Electrocardiographic Markers of Sudden Cardiac Death (Including Left Ventricular Hypertrophy)

Although the electrocardiograph (ECG) was invented more than 100 years ago, it remains the most commonly used test in clinical medicine. It is easy to perform, relatively cheap, and results are readily available. Interpretation, however, needs expertise and knowledge. New data, phenomenon, and syndromes are continually discovered by the ECG. It is important to differentiate between normal and abnormal ECGs first and then try to correlate the findings with clinical pathologies. Furthermore, the ECG is an integral part of the screening model for a variety of conditions such as channelopathies, athletes, preoperative risk profile, and remains the cardiologist's best friend.

Fragmented QRS for Risk Stratification in Patients Undergoing First Diagnostic Coronary Angiography

Background

Only a small proportion of patients referred for coronary angiography with suspected coronary artery disease (CAD) have the diagnosis of obstructive CAD confirmed by the exam. For this reason, further strategies for risk stratification are necessary.

Objective

To investigate the relationship of the presence of fragmented QRS (fQRS) on admission electrocardiogram with angiographically detected CAD and CAD severity in patients without known vascular diseases and myocardial fibrosis, undergoing first diagnostic coronary angiography.

Methods

We enrolled 336 consecutive patients undergoing coronary angiography for suspected CAD. The patients were divided into two groups according to the presence or absence of fQRS on admission. We compared the groups regarding the presence and severity of CAD.

Results

Seventy-nine (23.5%) patients had fQRS on admission. There was not a statistically significant difference between patients with fQRS (41.8%) and non-fQRS (30.4%), regarding the presence of CAD (p = 0.059). However, there was a statistically significant difference between patients with fQRS and non-fQRS regarding the presence of stenotic CAD (40.5% vs. 10.5%, p<0.001) and multi vessel disease (25,3% vs. 5.1%, p<0.001). The frequency of fQRS was significantly higher in patients with SYNTAX score >22 compared to patients with SYNTAX score ≤22.

Conclusions

Our findings suggest that fQRS may be an indicator of early-stage myocardial damage preceding the appearance of fibrosis and scar, and may be used for risk stratification in patients undergoing first diagnostic coronary angiography

The effect of circadian blood pressure pattern on presence of fragmented QRS complexes in hypertensive subjects

The association of deteriorated circadian blood pressure (BP) variability with presence of fragmented QRS (fQRS) on electrocardiography (ECG) is not clear. The present study aims to evaluate the relationship of BP patterns with presence of fQRS on ECG. A total of 338 consecutive newly diagnosed and never treated hypertensive patients who are without left ventricular hypertrophy and underwent 24-hour ambulatory BP monitoring were enrolled. Patients were classified as dippers, nondippers, and reverse dippers according to ambulatory BP monitoring results. The groups were compared regarding frequency of fQRS on ECG. The frequency of fQRS was significantly higher in reverse dippers compared with dippers (37.7% vs. 20.6%, P = .013). In multivariate logistic regression analysis, nighttime systolic BP was found to be an independent predictor of fQRS on ECG (P < .001, 95% confidence interval = 0.901-0.955). Other predictors of fQRS were daytime diastolic BP and age. Furthermore, fQRS was found to be an independent predictor of reverse dipping BP pattern in hypertensive patients (P = .004, odds ratio: 2.416, 95% confidence interval = 1.327-4.396). In conclusion, as a marker of fibrosis and higher fibrotic burden within myocardium, fQRS may be useful to determine the high-risk hypertensive patients in the absence of left ventricular hypertrophy.

ECG Parameters for Malignant Ventricular Arrhythmias: A Comprehensive Review

Many studies showed electrocardiogram (ECG) parameters are useful for predicting fatal ventricular arrhythmias (VAs). However, the studies have several shortcomings. Firstly, all studies lack of effective way to present behavior of various ECG parameters prior to the occurrence of the VAs. Secondly, they also lack of discussion on how to consider the parameters as abnormal. Thirdly, the reports do not include approaches to increase the detection accuracy for the abnormal patterns. The purpose of this study is to address the aforementioned issues. It identifies ten ECG parameters from various sources and then presents a review based on the identified parameters. From the review, it has been found that the increased risk of VAs can be represented by presence and certain abnormal range of the parameters. The variation of parameters range could be influenced by either gender or age. This study also has discovered the facts that averaging, outliers elimination and morphology detection algorithms can contribute to the detection accuracy.

Prognostic Significance of Fragmented QRS in Patients with Hypertrophic Cardiomyopathy

OBJECTIVES

The relationship between a fragmented QRS (fQRS) and clinical outcomes in patients with hypertrophic cardiomyopathy (HCM) remains unclear. This study aimed to investigate the prognostic significance of fQRS in patients with HCM.

METHODS

Between 2000 and 2012, 326 unrelated patients with HCM (72% male with a mean age of 52 years) were included and were divided into 2 groups: those with fQRS and those without fQRS.

RESULTS

A total of 105/326(32.2%) patients with HCM presented with fQRS at enrollment. During a follow-up of 5.3 ± 2.4 years, 33 patients died, 30 of cardiovascular disease (CVD). Cox regression analysis revealed that fQRS predicted a higher risk of all-cause mortality (adjusted hazard ratio [HR] 2.24; 95% confidence interval [CI] 1.08-4.64; p = 0.030) and CVD mortality (adjusted HR 2.68; 95% CI 1.22-5.91; p = 0.014). Our study also showed that fQRS increased the risk of heart failure-related death (adjusted HR 3.75; 95% CI 1.24-11.30; p = 0.019).

CONCLUSIONS

Our results indicate that fQRS is associated with adverse clinical outcomes in patients with HCM.

Assessment of the association between the presence of fragmented QRS and the predicted risk score of sudden cardiac death at 5 years in patients with hypertrophic cardiomyopathy

OBJECTIVE

It has been shown that the presence of fragmented QRS (fQRS) is associated with poor prognosis in many cardiovascular diseases and in patients with hypertrophic cardiomyopathy (HCM). However, no study has shown an association with the absolute risk score of sudden cardiac death. The aim of this study was to determine the relationship between QRS and the predicted risk score of sudden cardiac death at 5 years (HCM Risk-SCD) in HCM patients.

METHODS

In total, 115 consecutive HCM patients were included in this prospective observational study. The patients were divided into two groups according to the presence [fQRS(+) group (n=65)] or absence [fQRS(-) group (n=50)] of fQRS on a 12-lead electrocardiogram (ECG).

RESULTS

The HCM Risk-SCD (%) HCM Risk-SCD (>6%) values and some echocardiographic parameters, including ventricular extrasystole, ventricular tachycardia, cardiopulmonary resuscitation, implantable cardioverter defibrillator implantation, appropriate shock, and heart failure at the time of admission, were significantly higher in the fQRS(+) group than in the fQRS(-) group (all p<0.05). Both univariate and multivariate analyses revealed fQRS and New York Heart Association (NYHA) class as independent predictors of HCM Risk-SCD. In a receiver operating characteristic (ROC) curve analysis, an HCM Risk-SCD value of >4 was identified as an effective cut-off point in fQRS for HCM. An HCM Risk-SCD value of >4 yielded a sensitivity of 77% and a specificity of 76%.

CONCLUSION

fQRS is determined to be an independent high-risk indicator of HCM Risk-SCD. It seems to be associated with increased ventricular arrhythmias and some echocardiographic parameters.

Tp-e interval and Tp-e/QTc ratio as novel surrogate markers for prediction of ventricular arrhythmic events in hypertrophic cardiomyopathy

OBJECTIVE

Hypertrophic cardiomyopathy (HCM) as a common genetic heart disease characterized by ventricular hypertrophy and myocardial fibrosis is significantly associated with a higher risk of fatal ventricular arrhythmic events (VAEs). We aimed to assess the interval between the peak and the end of the electrocardiographic T wave (Tp-e) and Tp-e/corrected QT (QTc) ratio as candidate markers of ventricular arrhythmias in patients with HCM.

METHODS

In this single-center, prospective study, a total of 66 patients with HCM and 88 controls were enrolled. The patients were divided into two groups: those with VAEs (n=26) and those without VAEs (n=40). Tp-e interval and Tp-e/QTc ratio were measured using a 12-lead electrocardiogram.

RESULTS

Tp-e interval was significantly longer and Tp-e/QTc ratio were significantly higher in HCM patients than in the controls. In correlation analysis, maximal left ventricular (LV) thickness also has a significant positive correlation with Tp-e interval (r=0.422, p<0.001) and Tp-e/QTc ratio (r=0.348, p<0.001). Finally, multivariable regression analysis showed that a history of syncope, Tp-e interval [OR (odds ratio): 1.060; 95% confidence interval (CI): 1.005-1.117); p=0.012], Tp-e/QTc ratio (OR: 1.148; 95% CI: 1.086-1.204); p=0.049], and maximal LV thickness were independent predictors of VAEs in patients with HCM.

CONCLUSION

Our findings suggested that prolonged Tp-e interval and increased Tp-e/QTc ratio may be good surrogate markers for the prediction of VAEs in HCM.

Short-term Prognosis of Fragmented QRS Complex in Patients with Non-ST Elevated Acute Myocardial Infarction

Background:

There remains significant debate as to the relationship between fragmented QRS (fQRS) complexes on electrocardiogram (ECG) and acute myocardial infarction (AMI). Few studies have reported on this relationship in non-ST elevated AMI (NSTEMI), and thus, we attempt to assess this relationship and its potential short-term prognostic value.

Methods:

This was a single-center, observational, retrospective cohort study. A total of 513 consecutive patients (399 men, 114 women) with NSTEMI within 24 h who underwent coronary angiography at our department, between January 1, 2014, and December 31, 2014. Patients were divided into 2 groups according to the presence or absence of fQRS complex on the admission ECG. fQRS complexes were defined as the existence of an additional R’ or crochetage wave, notching in the nadir of the S wave, RS fragmentation, or QS complexes on 2 contiguous leads. All patients were followed up for 6 months, and all major adverse cardiac events (MACE) were recorded.

Results:

In this study, there were 285 patients with fQRS ECG in the 513 patients with NSTEMI. The number of patients with 0–2 coronary arteries narrowed by ≥50% in fQRS group were less while patients with 3 narrowed arteries were more than in the non-fQRS group (P = 0.042). There were fewer Killip Class I patients in the fQRS group (P = 0.019), while Killip Class II, III, and IV patients were more in the fQRS group than in the non-fQRS group (P = 0.019). Left ventricular ejection fraction levels were significantly lower in the fQRS group (P = 0.021). Baseline total cholesterol, low-density lipoprotein, creatinine, creatine kinase, homocysteine, high-sensitivity C-reactive protein (CRP), and red blood cells distribution width levels were significantly higher in the fQRS group. Total MACE (MACE, P = 0.028), revascularization (P = 0.005), and recurrent angina (P = 0.005) were also significantly greater in the fQRS group. On final logistic regression analysis, after adjusting for baseline variables, the following variables were independent predictors of fQRS: Coronary artery narrowing (P = 0.035), Killip classification (P = 0.026), and total cholesterol (P = 0.002). The following variables were found to be independent predictors of preoperative MACE: Hemoglobin (P = 0.000), gender (P = 0.026), fQRS (P = 0.016), and time from myocardial infarction to balloon or coronary artery bypasses grafting (P = 0.013).

Conclusions:

The fQRS complexes are commonly present in NSTEMI and the fQRS complexes are an independent predictor of MACE in NSTEMI patients. The number of narrowed coronary arteries, Killip classification, and total cholesterol are all independent predictors of the fQRS complexes.

The relationship between fragmented QRS and functional significance of coronary lesions

BACKGROUND

Recently fragmented QRS (fQRS) on electrocardiography (ECG) has been introduced as a predictor of myocardial scarring and myocardial ischemia in coronary artery disease (CAD).

OBJECTIVE

The aim of this study was to investigate the relationship between fQRS and fractional flow reserve (FFR) results in patients with the intermediate degree of coronary artery stenosis.

METHODS

A total of 301 consecutive patients who underwent coronary angiography (CAG) and FFR measurement for intermediate coronary artery stenosis were included in the study. The study patients were divided into two groups: the low FFR group (FFR value of ≤0.80) and normal FFR (FFR value of >0.80) group. Both groups were compared in terms of the presence of fQRS.

RESULTS

Of 301 patients, fQRS was detected in 128 (42.5%) and low FFR was detected in 115 (38.2%). In the low FFR group, fQRS was significantly higher (P<0.001). Multivariate analysis showed that fQRS was an independent predictor of myocardial ischemia in patients with intermediate coronary stenosis (OR=7.202, CI 95%, 4.195-12.367; p<0.001). The presence of fQRS had 70% sensitivity and 74% specificity for the prediction of FFR≤0.80.

CONCLUSION

In clinical practice, the presence of fQRS on ECG is associated with myocardial ischemia in patients with intermediate coronary stenosis.

Relationship between fragmented QRS and paradoxical septal motion in coronary artery bypass graft patients

OBJECTIVE

Paradoxical septal motion (PSM) can cause confusion in the assessment of ventricular function with scintigraphy even in the absence of ventricular septal damage and ischemia. Fragmented QRS (fQRS) is associated with various cardiac disorders. In this study, we aimed to determine the correlation between paradoxical septal motion and fQRS after coronary artery bypass grafting (CABG).

METHODS

We retrospectively reviewed the hospital records showing scintigraphic images and electrocardiograms (ECG) of the patients who had undergone CABG. The patients were classified based on the evaluation of motion and thickening of the septal wall. The patients with regular thickening of the septal wall and abnormal motion were classified as PSM (+) group. The patients with normal motion and thickening of the septal wall were classified as PSM (-) group. fQRS complexes are defined as various RSR patterns either with or without Q-waves on a 12-lead resting ECG.

RESULTS

PSM was found to be more common in fQRS patients (p < 0.001). PSM was seen in 91.4 % of cases with fQRS and in 79.8 % of cases without fQRS. No significant differences were found in the phase analysis parameters. A correlation was found between septal wall motion values and the presence of fQRS (r = 0.197, p = 0.012).

CONCLUSION

fQRS was associated with PSM. fQRS may cause PSM in patients with CABG without left bundle branch block due to a conduction defect. PSM and fQRS are predictive of cardiac mortality. Patients diagnosed with PSM and fQRS, should be monitored closely.

Atrial and ventricular arrhythmias in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease caused by mutations in genes coding for cardiac sarcomeres. HCM is the most common inherited heart disease, with a prevalence of 0.2%. There are multiple genetic variants that cause pleomorphic clinical attributes and disease characterized by myocardial disarray and myocardial hypertrophy. Patients are at an increased risk of atrial and ventricular arrhythmias. Management of these arrhythmias is complex. Atrial fibrillation is associated with increased mortality and thromboembolism. Ventricular arrhythmias are life threatening and best treated with an implantable defibrillator.

Risk Stratification in Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a hereditary primary myocardial disease that is most commonly due to mutations within genes encoding sarcomeric contractile proteins and is characterised by left ventricular hypertrophy in the absence of a cardiac or systemic cause. Although the overall prognosis is relatively good with an annual mortality rate <1 %, the propensity to potentially fatal ventricular arrhythmias is the most feared complication. The identification of patients at risk of arrhythmogenic sudden cardiac death (SCD) is an essential component in disease management. Aborted SCD and malignant ventricular arrhythmias are the most powerful risk factors for SCD and ICD implantation is recommended in such circumstances. The selection of patients who may benefit from ICD therapy for primary prevention purposes is more challenging. The heterogeneous nature of the disease and the variation in trigger factors provides an adequate explanation for the low predictive accuracy of most conventional risk factors in isolation. A new risk model for risk stratification proposed by the European Society of Cardiology HCM outcome group shows promise but requires validation in different cohorts. The ICD is the only effective therapy in preventing SCD for the disease with a relatively low adverse event rate, but most deaths occur in relatively young patients. However, it is also difficult to ignore the complications with the ICD, therefore, the strive to perfect risk stratification in HCM should continue to ensure that only the most high-risk patients receive an ICD.

The Predictive Value of Admission Fragmented QRS Complex for In-Hospital Cardiovascular Mortality of Patients with Type 1 Acute Aortic Dissection

BACKGROUND

Fragmented QRS (fQRS) arises from impaired ventricular depolarization due to heterogeneous electrical activation of ischemic and/or infarcted ventricular myocardium. The short- and long-term prognostic values of fQRS have been reported for myocardial infarction, heart failure, fatal cardiac arrhythmias, and sudden cardiac death. The aim of this study was to investigate the predictive value of admission fQRS complex for in-hospital cardiovascular mortality of patients with type 1 acute aortic dissection (AAD).

METHODS

In this retrospective study, 203 consecutive patients with type 1 AAD who had been admitted to either of two large-volume tertiary hospitals between December 2008 and October 2013 were included. The patients were divided into two groups according to the presence or absence of the fQRS complex on admission.

RESULTS

In-hospital cardiovascular mortality (P < 0.001), major adverse cardiovascular events (P < 0.001), acute renal failure (P = 0.022), multiorgan dysfunction (P < 0.001), and acute decompensated heart failure (P < 0.001) were observed to be significantly more frequent in the fQRS-positive group than in the fQRS-negative group. fQRS (odds ratio [95% confidence interval]: 4.184 [1.927-9.082], P < 0.001), operation duration (4.184 [1.927-9.082], P = 0.001), and Killip class IV (3.900 [1.699-8.955], P = 0.001) were found to be significant independent predictors of in-hospital cardiovascular mortality after adjustment of other risk factors in the multivariate analysis.

CONCLUSIONS

fQRS is a simple, inexpensive, and readily available electrocardiographic entity that provides an additional risk stratification level beyond that provided by conventional risk parameters in predicting in-hospital cardiovascular mortality in type 1 AAD.

Fragmented QRS predicts heart failure progression in patients with hypertrophic cardiomyopathy

BACKGROUND

Although fragmented QRS complex (frag-QRS) reflecting intra-ventricular conduction delay has been shown to be a prognostic marker for cardiac events, few data exist regarding the impact of frag-QRS on cardiac events in hypertrophic cardiomyopathy (HCM).

METHODS AND RESULTS

Ninety-four HCM patients (56 male; mean age, 58 ± 17 years) were retrospectively investigated. Frag-QRS was defined as the presence of various RsR' patterns in at least 2 contiguous ECG leads. Major arrhythmic events (MAE) were defined as sudden cardiac death, and combined sustained ventricular tachycardia/ventricular fibrillation. New-onset atrial fibrillation (AF) was diagnosed based on ECG during provisional or routine medical examination. Heart failure (HF) with hospitalization was defined as hospital admission due to subjective or objective symptoms. Frag-QRS was detected in 31 patients (33%).TNNI3 was the most frequent disease-causing gene. Median follow-up was 4.6 years. The 4-year cumulative survival rates of cardiac death, MAE, new-onset AF and HF with hospitalization were 97.6%, 94.6%, 87.5% and 89.3%, respectively. On multivariate analysis, frag-QRS was significantly associated with HF with hospitalization (adjusted hazard ratios [95% confidence intervals]: 5.4 [1.2-36], P=0.03). Moreover, HF-free survival was significantly lower in the frag-QRS (+) group compared to the frag-QRS (-) group (79.0% vs. 95.1%, P=0.03).

CONCLUSIONS

Frag-QRS is associated with HF with hospitalization in HCM patients who had a unique distribution of gene mutations.

Fragmented QRS on surface electrocardiogram is not a reliable predictor of myocardial scar, angiographic coronary disease or long term adverse outcomes

PURPOSE

Conflicting evidence remains regarding the value of fragmented QRS (fQRS) on surface electrocardiogram (EKG). We present the 5-year outcome of patients with fQRS on EKG and its correlation to SPECT and coronary angiography (CA).

METHODS

We retrospectively studied EKG's in 248 consecutive patients undergoing SPECT and CA with known or suspected coronary artery disease (CAD). The presence of fQRS or Q waves in two contiguous EKG leads was correlated with major coronary artery distributions on SPECT and cath. Patients with bundle-branch block, paced-rhythm or absence of EKG within one month of SPECT were excluded. The final EKG data for 238 patients were analyzed and compared with myocardial scar on SPECT and the presence of significant (>50%) coronary stenosis on CA. Predictors of MACE (death, MI, heart failure) were evaluated. Freedom from all-cause mortality was assessed by Kaplan-Meier analysis.

RESULTS

Of 238 patients, no significant difference was noted in the presence of scar on SPECT in fQRS (3/77; 3.8%) versus no fQRS (11/161; 6.8%) (P=0.56); or CA based CAD (55/77; 71% fQRS) and no fQRS (99/161, 61.4%) (P=0.20). EKG Q wave presence was similar in both groups: (12/77; 15.5% fQRS), (17/161; 10.5% no fQRS) (P=0.3). Patients with CA based significant LAD disease were 3.680 times more likely to have fQRS (P=0.04), however, fQRS was not significantly associated with MACE (P=0.92) or all-cause mortality (P=0.93).

CONCLUSIONS

This study does not support routine assessment of fQRS on surface EKG as a reliable predictor of SPECT myocardial scar, MACE or all-cause mortality over a long period of follow-up.

Significance of fragmented QRS complexes for identifying left ventricular hypertrophy in patients with hypertension

BACKGROUND

Fragmented QRS complexes (fQRS) were associated with left ventricular mass (LVM) in hypertensive patients. Our study aimed to investigate the association between fQRS and left ventricular hypertrophy (LVH) in hypertensive patients.

METHODS

Two hundred thirty-six hypertensive patients were divided into fQRS group and non-fQRS group. fQRS were defined as the presence of an additional R wave, notching in the R or S wave, or the presence of >1 R' in two contiguous leads. Echocardiography was used to detect LVH.

RESULTS

Patients with fQRS had higher levels of LVM than patients without fQRS (181.55 ± 65.64 g vs. 149.21 ± 35.08 g, P < 0.001). Receiver operating characteristic curves showed areas under the curve was 0.62 for fQRS (95% CI 0.54-0.69, P = 0.003). In univariate analyses, the presence of fQRS on ECG was positively associated with LVM. Multiple regression analyses found fQRS was associated with LVM, independently.

CONCLUSION

fQRS is a common electrocardiographic phenomenon in patients with hypertension. Although the diagnostic value for LVH is limited, the presence of fQRS on ECG is associated with a higher risk for worse LVH.

Hypertrophic cardiomyopathy: Can the noninvasive diagnostic testing identify high risk patients?

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death (SCD) in the young, particularly among athletes. Identifying high risk individuals is very important for SCD prevention. The purpose of this review is to stress that noninvasive diagnostic testing is important for risk assessment. Extreme left ventricular hypertrophy and documented ventricular tachycardia and fibrillation increase the risk of SCD. Fragmented QRS and T wave inversion in multiple leads are more common in high risk patients. Cardiac magnetic resonance imaging provides complete visualization of the left ventricular chamber, allowing precise localization of the distribution of hypertrophy and measurement of wall thickness and cardiac mass. Moreover, with late gadolinium enhancement, patchy myocardial fibrosis within the area of hypertrophy can be detected, which is also helpful in risk stratification. Genetic testing is encouraged in all cases, especially in those with a family history of HCM and SCD.

Fragmented QRS is associated with frequency of premature ventricular contractions in patients without overt cardiac disease

Objective:

In this study, we aimed to demonstrate whether the presence of fragmented QRS (fQRS) is associated with the frequency of premature ventricular contractions (PVCs).

Methods:

We retrospectively analyzed 282 cases by 24-hour Holter monitorings (HMs) between August 2012 and February 2013. Firstly, the patients were divided into 2 groups with respect to presence of fQRS and then divided into 3 groups with respect to frequency of PVCs as Group 1: seldom PVC (<120 PVCs/day), Group 2: moderate-frequency PVC (120-720 PVCs/day), and Group 3: frequent PVC (>720 PVCs/day). We investigated the predictors of frequent PVCs by using multinomial logistic regression analysis.

Results:

Ninety-eight patients had fQRS. There was no difference between the 2 groups with respect to body mass index, gender, hypertension, and diabetes mellitus. Patients with fQRS were older (54.9±15.6 vs. 47.0±16.3, p<0.001) and had more family history of coronary artery disease (25% vs. 13%, p=0.012). Patients with fQRS was more likely to be on aspirin therapy (28.6% vs. 10.4%, p<0.001) and have a larger left atrium diameter (33.5±5.7 vs. 30.4±5.8, p=0.001). Presence of fQRS was significantly associated with the frequency of PVCs (for frequent PVC 27.7% vs. 7.6%, p<0.001; for moderate-frequency PVC 18.4% vs. 11.4%, p=0.012); 26.2% of Group 1 (n=202) had fQRS, 46.2% of Group 2 (n=39) had fQRS, and 65.9% of Group 3 (n=41) had fQRS. In the multinomial regression analysis, only age (odds ratio: 4.24, 95% confidence interval 2.08-8.64, p=0.001) and fQRS (odds ratio: 2.11, 95% confidence interval 1.00-4.45, p=0.05) were predictors of frequent PVCs.

Conclusion:

This study demonstrated that the presence of fQRS is associated with frequent PVCs in patients without overt structural heart disease.

Assessment of the relationship between fragmented QRS and cardiac iron overload in patients with beta-thalassemia major

Objective:

Beta-thalassemia major (TM) is a genetic hemoglobin disorder causing chronic hemolytic anemia. Since cardiac insufficiency and arrhythmias are the primary causes of mortality in such patients, monitoring of cardiac iron load is important in management of the disorder. The purpose of this study was to investigate the importance of fragmented QRS (fQRS) and its relation to the cardiac T2* value for the evaluation of cardiac iron load in TM patients.

Methods:

This retrospective study included 103 TM patients. The patients’ T2* values, measured by cardiac MRI and 12-lead surface ECGs, were interpreted. The cardiac T2* values under 20 were considered as cardiac iron overload. The relationship between the cardiac T2* value and fQRS in ECG was investigated.

Results:

The median age of the patients was 22.6±6.6 years. All patients were on regular blood transfusions and iron chelators. The patients had no risk factors for coronary artery disease. In 50 (48%) patients fQRS was detected, and in 37 (74%) of these the T2* values were low. 86% of patients with cardiac involvement (37) had fQRS, but 22% of patients with non-involvement (13) had fQRS (p<0.001).

Conclusion:

Since cardiac involvement is the primary cause of mortality in TM patients, the early diagnosis of cardiac dysfunction is of vital importance. The search for fQRS in the ECGs of these patients, particularly when cardiac T2* values cannot be determined and followed, is a non-expensive and easy-to-attain method for therapy management.