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 ...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.展开更多
Brugada phenocopies(BrP) are clinical entities that are etiologically distinct from true congenital Brugada syndrome. BrP are characterized by type 1 or type 2 Brugada electrocardiogram(ECG) patterns in precordial lea...Brugada phenocopies(BrP) are clinical entities that are etiologically distinct from true congenital Brugada syndrome. BrP are characterized by type 1 or type 2 Brugada electrocardiogram(ECG) patterns in precordial leads V1-V3. However, BrP are elicited by various un-derlying clinical conditions such as myocardial ischemia, pulmonary embolism, electrolyte abnormalities, or poor ECG filters. Upon resolution of the inciting underlying pathological condition, the BrP ECG subsequently nor-malizes. To date, reports have documented BrP in the context of singular clinical events. More recently, recur-rent BrP has been demonstrated in the context of re-current hypokalemia. This demonstrates clinical repro-ducibility, thereby advancing the concept of this new ECG phenomenon. The key to further understanding the pathophysiological mechanisms behind BrP requires experimental model validation in which these phenom-ena are reproduced under strictly controlled environ-mental conditions. The development of these validation models will help us determine whether BrP are tran-sient alterations of sodium channels that are not repro-ducible with a sodium channel provocative test or al-ternatively, a malfunction of other ion channels. In this editorial, we discuss the conceptual emergence of BrP as a new ECG phenomenon, review the progress made to date and identify opportunities for further investiga-tion. In addition, we also encourage investigators that are currently reporting on these cases to use the term BrP in order to facilitate literature searches and to help establish this emerging concept.展开更多
BACKGROUND Cardiac magnetic resonance(CMR)is a unique tool for non-invasive tissue characterization,especially for identifying fibrosis.AIM To present the existing data regarding the association of electrocardiographi...BACKGROUND Cardiac magnetic resonance(CMR)is a unique tool for non-invasive tissue characterization,especially for identifying fibrosis.AIM To present the existing data regarding the association of electrocardiographic(ECG)markers with myocardial fibrosis identified by CMR-late gadolinium enhancement(LGE).METHODS A systematic search was performed for identifying the relevant studies in Medline and Cochrane databases through February 2021.In addition,we conducted a relevant search by Reference Citation Analysis(RCA)(https://www.referencecitationanalysis.com).RESULTS A total of 32 studies were included.In hypertrophic cardiomyopathy(HCM),fragmented QRS(fQRS)is related to the presence and extent of myocardial fibrosis.fQRS and abnormal Q waves are associated with LGE in ischemic cardiomyopathy patients,while fQRS has also been related to fibrosis in myocarditis.Selvester score,abnormal Q waves,and notched QRS have also been associated with LGE.Repolarization abnormalities as reflected by increased Tp-Te,negative Twaves,and higher QT dispersion are related to myocardial fibrosis in HCM patients.In patients with Duchenne muscular dystrophy,a significant correlation between fQRS and the amount of myocardial fibrosis as assessed by LGE-CMR was observed.In atrial fibrillation patients,advanced inter-atrial block is defined as P-wave duration≥120 ms,and biphasic morphology in inferior leads is related to left atrial fibrosis.CONCLUSION Myocardial fibrosis,a reliable marker of prognosis in a broad spectrum of cardiovascular diseases,can be easily understood with an easily applicable ECG.However,more data is needed on a specific disease basis to study the association of ECG markers and myocardial fibrosis as depicted by CMR.展开更多
Background:Right ventricular pacing disrupts atrioventricular synchrony and increases the risk of atrial fi brillation(AF).However,whether algorithms for minimizing ventricular pacing reduce the incidence of AF remain...Background:Right ventricular pacing disrupts atrioventricular synchrony and increases the risk of atrial fi brillation(AF).However,whether algorithms for minimizing ventricular pacing reduce the incidence of AF remains controversial.Therefore,we conducted a systematic review and meta-analysis to compare the incidence of AF between minimizing ventricular pacing and conventional pacing protocols in patients with pacemakers implanted.Methods:The PubMed,Embase,and Cochrane Library databases were searched up to August 1,2017,for randomized controlled trials that reported the incidence of AF in patients with and without the use of algorithms for minimizing ventricular pacing.Results:Eleven studies comprising 5705 participants(61%males,mean age 71 years[standard deviation 11 years])were fi nally included in the analysis.The mean follow-up duration was 24 months.Use of algorithms for minimizing ventricular pacing signifi cantly reduced the incidence of AF,with an odds ratio of 0.74(95%confi dence interval 0.55–1.00;P<0.05).There was moderate heterogeneity among studies(I 2=63%).Conclusions:The incidence of AF was reduced by 26%with use of algorithms for minimizing ventricular pacing.The incorporation of such algorithms in routine clinical practice should in theory lead to a decrease in AF-related morbidity and mortality.展开更多
The 12-lead electrocardiogram(ECG)is a routinely performed test but is susceptible to misinterpretation even by experienced physicians.We report a case of a 72-year-old lady with no prior cardiac history presented to ...The 12-lead electrocardiogram(ECG)is a routinely performed test but is susceptible to misinterpretation even by experienced physicians.We report a case of a 72-year-old lady with no prior cardiac history presented to our hospital with atypical chest pain.Her initial electrocardiogram shows an initial ST depression followed by positive defl ections leads I and aVL.Non-physiological ST segment and T-wave changes are also observed in the precordial leads V2 to V6.By contrast,these abnormalities are notably absent in lead II.A repeat of the ECG taken 30 minutes later reveals the resolution of most abnormalities seen in the initial ECG on a background of high-frequency noise in the limb leads.She was referred to the cardiology department for further management.An urgent echocardiogram revealed no regional wall motion abnormalities with preserved ejection fraction,and her coronary angiogram revealed no signifi cant coro-nary stenosis.This case illustrates the importance of understanding different factors that can cause ST segment abnor-malities,notably artifactual changes that can mimic ST segment myocardial infarction.展开更多
文摘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.
文摘Brugada phenocopies(BrP) are clinical entities that are etiologically distinct from true congenital Brugada syndrome. BrP are characterized by type 1 or type 2 Brugada electrocardiogram(ECG) patterns in precordial leads V1-V3. However, BrP are elicited by various un-derlying clinical conditions such as myocardial ischemia, pulmonary embolism, electrolyte abnormalities, or poor ECG filters. Upon resolution of the inciting underlying pathological condition, the BrP ECG subsequently nor-malizes. To date, reports have documented BrP in the context of singular clinical events. More recently, recur-rent BrP has been demonstrated in the context of re-current hypokalemia. This demonstrates clinical repro-ducibility, thereby advancing the concept of this new ECG phenomenon. The key to further understanding the pathophysiological mechanisms behind BrP requires experimental model validation in which these phenom-ena are reproduced under strictly controlled environ-mental conditions. The development of these validation models will help us determine whether BrP are tran-sient alterations of sodium channels that are not repro-ducible with a sodium channel provocative test or al-ternatively, a malfunction of other ion channels. In this editorial, we discuss the conceptual emergence of BrP as a new ECG phenomenon, review the progress made to date and identify opportunities for further investiga-tion. In addition, we also encourage investigators that are currently reporting on these cases to use the term BrP in order to facilitate literature searches and to help establish this emerging concept.
文摘BACKGROUND Cardiac magnetic resonance(CMR)is a unique tool for non-invasive tissue characterization,especially for identifying fibrosis.AIM To present the existing data regarding the association of electrocardiographic(ECG)markers with myocardial fibrosis identified by CMR-late gadolinium enhancement(LGE).METHODS A systematic search was performed for identifying the relevant studies in Medline and Cochrane databases through February 2021.In addition,we conducted a relevant search by Reference Citation Analysis(RCA)(https://www.referencecitationanalysis.com).RESULTS A total of 32 studies were included.In hypertrophic cardiomyopathy(HCM),fragmented QRS(fQRS)is related to the presence and extent of myocardial fibrosis.fQRS and abnormal Q waves are associated with LGE in ischemic cardiomyopathy patients,while fQRS has also been related to fibrosis in myocarditis.Selvester score,abnormal Q waves,and notched QRS have also been associated with LGE.Repolarization abnormalities as reflected by increased Tp-Te,negative Twaves,and higher QT dispersion are related to myocardial fibrosis in HCM patients.In patients with Duchenne muscular dystrophy,a significant correlation between fQRS and the amount of myocardial fibrosis as assessed by LGE-CMR was observed.In atrial fibrillation patients,advanced inter-atrial block is defined as P-wave duration≥120 ms,and biphasic morphology in inferior leads is related to left atrial fibrosis.CONCLUSION Myocardial fibrosis,a reliable marker of prognosis in a broad spectrum of cardiovascular diseases,can be easily understood with an easily applicable ECG.However,more data is needed on a specific disease basis to study the association of ECG markers and myocardial fibrosis as depicted by CMR.
文摘Background:Right ventricular pacing disrupts atrioventricular synchrony and increases the risk of atrial fi brillation(AF).However,whether algorithms for minimizing ventricular pacing reduce the incidence of AF remains controversial.Therefore,we conducted a systematic review and meta-analysis to compare the incidence of AF between minimizing ventricular pacing and conventional pacing protocols in patients with pacemakers implanted.Methods:The PubMed,Embase,and Cochrane Library databases were searched up to August 1,2017,for randomized controlled trials that reported the incidence of AF in patients with and without the use of algorithms for minimizing ventricular pacing.Results:Eleven studies comprising 5705 participants(61%males,mean age 71 years[standard deviation 11 years])were fi nally included in the analysis.The mean follow-up duration was 24 months.Use of algorithms for minimizing ventricular pacing signifi cantly reduced the incidence of AF,with an odds ratio of 0.74(95%confi dence interval 0.55–1.00;P<0.05).There was moderate heterogeneity among studies(I 2=63%).Conclusions:The incidence of AF was reduced by 26%with use of algorithms for minimizing ventricular pacing.The incorporation of such algorithms in routine clinical practice should in theory lead to a decrease in AF-related morbidity and mortality.
文摘The 12-lead electrocardiogram(ECG)is a routinely performed test but is susceptible to misinterpretation even by experienced physicians.We report a case of a 72-year-old lady with no prior cardiac history presented to our hospital with atypical chest pain.Her initial electrocardiogram shows an initial ST depression followed by positive defl ections leads I and aVL.Non-physiological ST segment and T-wave changes are also observed in the precordial leads V2 to V6.By contrast,these abnormalities are notably absent in lead II.A repeat of the ECG taken 30 minutes later reveals the resolution of most abnormalities seen in the initial ECG on a background of high-frequency noise in the limb leads.She was referred to the cardiology department for further management.An urgent echocardiogram revealed no regional wall motion abnormalities with preserved ejection fraction,and her coronary angiogram revealed no signifi cant coro-nary stenosis.This case illustrates the importance of understanding different factors that can cause ST segment abnor-malities,notably artifactual changes that can mimic ST segment myocardial infarction.
