Predicting the outcome in patients with unexplained syncope and suspected cardiac cause: Role of electrophysiologic studies

Objective: Unexplained syncope is a challenge facing electrophysiologists. The prognosis varies widely depending on underlying causes, specially, cardiac ones. We sought to determine the abnormal electrophysiolgic (EP) study results as predictors of prognosis in syncope patients with suspected cardiac cause and risk factors associated with mortality. Methods: A total of 227 consecutive patients with unexplained syncope were prospectively enrolled in this study. EP study was performed in 177 patients in base of inclusion criteria. These patients, in whom a cardiac cause of syncope was suspected, underwent EP study and if negative, head-up tilts test (HUTT). Complete follow-up was obtained for 132 patients for 20.0±10.8 months. Results: A cardiac cause of syncope was established in 35, a neurally mediated syncope in 35.6, and in the rest 29.4 the cause of syncope remained unexplained despite a throughout neurologic and cardiologic evaluation. Logistic analysis revealed that the significant predictors of a cardiac cause of syncope were the absence of prodromal symptoms, left bundle branch block (LBBB), sever left ventricle (LV) dysfunction and male gender. At logistic analysis, the presence of LBBB (OR=6.63; 95 CI: 1.09-40) was significantly associated with outcome of death. Conclusion: The present study provides evidence that presence of LBBB, abnormal EP study result and structural heart disease (SHD) have prognostic value in patients with suspected cardiac cause of syncope. The patients with SHD and unexplained syncope who had a negative EP study have a good long-term prognosis even in the presence of LV dysfunction. © 2015 by Turkish Society of Cardiology

Predicting the outcome in patients with unexplained syncope and suspected cardiac cause: Role of electrophysiologic studies Kalp nedenli oldu�undan ��phe edilen ve a�ıklanamayan senkoplu bir hastada sonucun kestirilmesi

Objective: Unexplained syncope is a challenge facing electrophysiologists. The prognosis varies widely depending on underlying causes, specially, cardiac ones. We sought to determine the abnormal electrophysiolgic (EP) study results as predictors of prognosis in syncope patients with suspected cardiac cause and risk factors associated with mortality. Methods: A total of 227 consecutive patients with unexplained syncope were prospectively enrolled in this study. EP study was performed in 177 patients in base of inclusion criteria. These patients, in whom a cardiac cause of syncope was suspected, underwent EP study and if negative, head-up tilts test (HUTT). Complete follow-up was obtained for 132 patients for 20.0�10.8 months. Results: A cardiac cause of syncope was established in 35, a neurally mediated syncope in 35.6, and in the rest 29.4 the cause of syncope remained unexplained despite a throughout neurologic and cardiologic evaluation. Logistic analysis revealed that the significant predictors of a cardiac cause of syncope were the absence of prodromal symptoms, left bundle branch block (LBBB), sever left ventricle (LV) dysfunction and male gender. At logistic analysis, the presence of LBBB (OR=6.63; 95 CI: 1.09-40) was significantly associated with outcome of death. Conclusion: The present study provides evidence that presence of LBBB, abnormal EP study result and structural heart disease (SHD) have prognostic value in patients with suspected cardiac cause of syncope. The patients with SHD and unexplained syncope who had a negative EP study have a good long-term prognosis even in the presence of LV dysfunction. � 2015 by Turkish Society of Cardiology

Atrial Fibrillation and Stroke:State-of-the-art and future directions

Stroke is a major complication of atrial fibrillation (AF). About 25% of ischaemic stroke are cardio-embolic in origin; AF is the most common cause of those.1 Nonvalvular AF carries a 5-fold increased risk of stroke,2 while AF related to mitral stenosis increases the risk of stroke by 20-fold.3 The attributable risk of stroke for AF increases with age unlike other factors such as hypertension for instance.4When the AF is asymptomatic but detected on a cardiac implantable electronic device (CIED) or a wearable monitor, it is described as being subclinical. It is suspected that subclinical AF might be the cause of cryptogenic strokes (i.e., strokes of unknown aetiology).5 While previous studies showed that atrial high-rate events (AHREs) detected on a CIED were associated with increased risk of stroke,5,6 treating such episodes with anticoagulation has not been shown to reduce the risk of stroke. In fact, anticoagulation in these cases resulted in higher incidence of a composite of death or major bleeding, mainly driven by the increased risk of bleeding.7Not only that AF can cause stroke and vice versa,8 but stroke patients with AF were shown have higher stroke severity and mortality compared to those without.9 The effect of AF on mortality rate was primarily driven by stroke severity.9 The worse clinical and imaging outcome in AF-related strokes was attributed to bigger volumes of more severely hypo-perfused tissues, resulting in larger infarct size and higher risk of haemorrhagic transformation.10In this narrative review article, we provided an overview of the burden of AF and stroke, the complex interplay between the two conditions, as well as the treatment and secondary prevention of stroke in patients with AF. We comprehensively discussed the current evidence and the ongoing conundrums, and highlighted the future directions on the topic

Early Risk stratification for Arrhythmic death in Patients with ST-Elevation Myocardial Infarction

BACKGROUND: Sudden cardiac death is a leading cause of death in patients with ST-elevation myocardial infarction (MI). According to high cost of modern therapeutic modalities it is of paramount importance to define protocols for risk stratification of post-MI patients before considering expensive devices such as implantable cardioverter-defibrillator. METHODS: One hundred and thirty seven patients with acute ST-elevation MI were selected and underwent echocardiographic study, holter monitoring and signal-averaged electrocardiography (SAECG). Then, the patients were followed for 12 ±3 months. RESULTS: During follow-up, 13 deaths (9.5%) occurred; nine cases happened as sudden cardiac death (6.6%). The effect of ejection fraction (EF) less than 40% on occurrence of arrhythmic events was significant (P<0.001). Sensitivity and positive predictive value of EF<40% was 100% and 76.95% respectively. Although with lesser sensitivity and predictive power than EF<40%, abnormal heart rate variability (HRV) and SAECG had also significant effects on occurrence of sudden death (P=0.02 and P=0.003 respectively). Nonsustained ventricular tachycardia was not significantly related to risk of sudden death in this study (P=0.20). CONCLUSION: This study indicated that EF less than 40% is the most powerful predictor of sudden cardiac death in post MI patients. Abnormal HRV and SAECG are also important predictors and can be added to EF for better risk stratification

Catheter Ablation of the Accessory Pathway in the Asymptomatic Patient with Wolff-Parkinson-White

Wolff-Parkinson-White (WPW) is a condition in which an accessory conduction pathway exists within the heart. This accessory pathway may or may not cause symptoms, in fact, the first manifestation of the condition may be sudden cardiac death. The management of this condition in asymptomatic individuals is controversial. The purpose of this research and literature review is to analyze the safety and efficacy associated with invasive catheter ablation of the accessory pathway, in comparison to risk of sudden cardiac death and malignant arrythmias in non-ablated, asymptomatic individuals with WPW. In this review, five databases were searched including CINAHL, Clinical Key, PubMed, Cochrane Library, and Dynamed Plus. Both keyword and mesh terms were used to define a set of the literature discussing Wolff-Parkinson-White, ventricular preexcitation, radiofrequency catheter ablation, and sudden cardiac death. Works chosen for review were published from 2009 to 2019, and included surveys, case control studies, and cohort studies. Sources that were excluded included those published prior to 2009, systematic reviews, and meta-analysis, in order to exclusively include original research. Much of the research suggests that electrophysiologists do not currently have an adequate evidence-based recommendation for the management of the asymptomatic patient with WPW. The methodology and safety of the ablation procedures may have evolved over time, making it difficult with the current data available to conclude the safety and efficacy of modern radiofrequency catheter ablation. Research also appears to be lacking longitudinal studies analyzing the outcomes of the non-ablated individuals. Future research is necessary to develop a guideline to direct decision to ablate the asymptomatic patient according to predetermined criteria and patient factors

Management of asymptomatic arrhythmias: a European Heart Rhythm Association (EHRA) consensus document, endorsed by the Heart Failure Association (HFA), Heart Rhythm Society (HRS), Asia Pacific Heart Rhythm Society (APHRS), Cardiac Arrhythmia Society of Southern Africa (CASSA), and Latin America Heart Rhythm Society (LAHRS).

Asymptomatic arrhythmias are frequently encountered in clinical practice. Although studies specifically dedicated to these asymptomatic arrhythmias are lacking, many arrhythmias still require proper diagnostic and prognostic evaluation and treatment to avoid severe consequences, such as stroke or systemic emboli, heart failure, or sudden cardiac death. The present document reviews the evidence, where available, and attempts to reach a consensus, where evidence is insufficient or conflicting

Yield of Diagnostic Tests in the Evaluation of Syncopal Episodes in Older Patients

ABSTRACT: YIELD OF DIAGNOSTIC TESTS IN THE EVALUATION OF SYNCOPAL EPISODES IN OLDER PATIENTS Mallika L. Mendu, Gail McAvay, Rachel Lampert, Jonathan Stoehr, Mary E. Tinetti, Department of Internal Medicine, Department of Epidemiology and Public Health Yale University, School of Medicine, New Haven, CT Syncopal episodes are common among older adults; etiologies range from benign to life-threatening. We determined the frequency, yield, and costs of tests obtained to evaluate older persons with syncope. We also calculated the cost per test yield and determined whether the San Francisco Syncope Rule (SFSR) improved test yield. Review of 2,106 consecutive patients 65 years and older admitted following a syncopal episode. Electrocardiograms (99%), telemetry (95%), cardiac enzymes (95%), and head computed tomography (CT) (63%) were the most frequently obtained tests. Cardiac enzymes, CTs, echocardiograms, carotid ultrasounds, and electroencephalography all affected diagnosis or management in \u3c5% of cases and helped determine etiology of syncope \u3c 2% of the time. Postural blood pressure, performed in only 38% of episodes, had the highest yield with respect to affecting diagnosis (18-26%) or management (25-30%) and determining etiology of the syncopal episode (15-21%). The cost per test affecting diagnosis or management was highest for electroencephalography ($32,973), CT ($24,881), and cardiac enzymes ($22,397) and lowest for postural blood pressure ($17-$20). The yields and costs for cardiac tests were better among patients meeting, than not meeting, SFSR. For example, the cost per cardiac enzymes affecting diagnosis or management was$10,331 in those meeting, versus $111,518 in those not meeting, the SFSR. Many unnecessary tests are obtained to evaluate syncope. Selecting tests based on history and examination and prioritizing less expensive and higher yield tests would ensure a more informed and cost-effective approach to evaluating older patients with syncope

Thrombolysis in Acute Myocardial Infarction: An Electrocardiographic Study

The value of thrombolytic therapy in the treatment of acute myocardial infarction is now unchallenged following the publication of large scale clinical trials showing an impressive reduction in mortality. Intravenous administration of a thrombolytic agent in the early hours of myocardial infarction is established practice in all hospitals, from district generals to specialized cardiac centres. The aim is to obtain a patent artery, improve left ventricular function and decrease mortality. The effectiveness of intravenous therapy obviates the need for acute angiography and intracoronary administration, but a definitive statement concerning whether reperfusion has occurred cannot be made. The 12 lead ECG undergoes well recognised dynamic changes in the early phase of myocardial infarction. Successful lysis, either induced or spontaneous, will modify these changes. Whether these modifications can be quantified and used as simple non invasive tests of reperfusion, myocardial salvage and infarct size has caused much speculation. To have such a simple, widely available, reproducible and inexpensive tool would be highly desirable in a clinical setting. This thesis has addressed these questions. The first study demonstrated the rapid fall in ST segment elevation occurring in response to thrombolysis, and introduced a measurement which expresses this fall as a proportion of the admission value. This is termed the Fractional Change and can be applied to either 24 hour tape recordings or to the 12 lead ECG. A Fractional Change Value > 0.5 occurring by 2-3 hours following therapy is highly specific and sensitive for reperfusion. The next study examined whether an electrocardiographic marker of infarct size, the QRS score, was attenuated in patients achieving successful reperfusion compared with a historical cohort of patients with infarctions given no therapy other than simple analgesia. Only patients with anterior infarcts were studied, and although both groups had similar areas of myocardium at jeopardy on admission, the group of patients achieving successful reperfusion had a significant reduction in the QRS score at 48 hours compared to the control group. These initial studies showed that dynamic changes in the ECG can reflect both reperfusion and myocardial salvage, but are limited in that they were performed in relatively small numbers, and the ECG measurements were made and tabulated manually. A method for digitizing 12 lead ECG's with subsequent computer storage of data for comparative analysis has been developed, and incorporates an automatic QRS scoring system. The developmental work involved in setting this system up and its subsequent validation with inter- and intra-observer variation studies is presented in Chapter 5. This system was then used to follow the sequential ECG changes in a prospective angiographically controlled, double blind randomised trial of 128 patients comparing anistreplase with streptokinase. The 90 minute patency rates for both drugs were found to be the same (anistreplase 55%, streptokinase 53%) . Coronary angiography performed at 90 minutes post therapy allowed a detailed correlation between ECG changes on admission and acute coronary anatomy. The findings of this particular study showed that the height of ST segment elevation does not bear any relation to the age of the infarct, that there is a high incidence of reciprocal change early in the course of infarction, and that this is not related to coexisting disease or remote ischaemia, but is likely to be an electrocardiographic mirror phenomenon. Examining the resolution of ST segment elevation and depression showed that it was the rate of fall which discriminates patent from non patent arteries, and that using a Fractional Change Value of 0. 5 to detect reperfusion, calculated at 2 hours post treatment from a single lead showing maximal ST segment elevation, gave the best sensitivity (81%) and specificity (60%), when compared with a number of different parameters. In addition, it appears that the presence of collaterals supplying the infarct area could result in a high Fractional Change Value despite no antegrade perfusion. This study also confirmed that achievement of a patent artery early (i.e. before 90 minutes) significantly attenuated Q wave development, R wave loss and the QRS score in anterior infarction, but did not affect electrocardiographic markers of infarct size when applied to inferior infarcts. In summary, this thesis provides a detailed study of the electrocardiographic changes taking place in acute myocardial infarction, especially as a consequence of treating with thrombolysis, quantitates these changes and shows where they may be used in a clinical setting as non-invasive tests to aid patient management

Electrocardiologic and related methods of non-invasive detection and risk stratification in myocardial ischemia: state of the art and perspectives

Background: Electrocardiographic methods still provide the bulk of cardiovascular diagnostics. Cardiac ischemia is associated with typical alterations in cardiac biosignals that have to be measured, analyzed by mathematical algorithms and allegorized for further clinical diagnostics. The fast growing fields of biomedical engineering and applied sciences are intensely focused on generating new approaches to cardiac biosignal analysis for diagnosis and risk stratification in myocardial ischemia