Myocardial ischemia and ventricular tachycardia on continuous electrocardiographic monitoring and risk of cardiovascular outcomes after non-ST-segment elevation acute coronary syndrome (from the MERLIN-TIMI 36 Trial)

[Catheter ablation of ventricular tachycardia in patients with structural heart disease]

Ventricular cardiac rhythm disorders are potentially life-threatening arrhythmias. Ventricular tachycardia (VT) in patients with structural heart disease carries an increased risk of sudden cardiac death. Interventional radiofrequency catheter ablation is increasingly becoming the focus of treatment for ventricular arrhythmias. So far, no randomized study has been able to demonstrate a reduction in mortality; however, depending on the existing cardiomyopathy, interventional VT ablation has proven to be more effective for rhythm stabilization than antiarrhythmic therapy and is subsequently associated with improve quality of life through reduced implantable cardioverter defibrillator (ICD) treatment. The aim of this work is to discuss the pathophysiology, mechanism and treatment of VT with structural heart disease in order to define the role of catheter ablation.

Myocardial Ischemia Induced by 5-Fluorouracil: A Prospective Electrocardiographic and Cardiac Biomarker Study

BACKGROUND

Cardiotoxicity induced by 5-fluorouracil (5-FU) is well known but poorly understood. In this study, we undertook ECG recording (Holter) and analyses of the biomarkers troponin and copeptin in patients receiving 5-FU to increase our understanding of the cardiotoxicity.

SUBJECTS, MATERIALS, AND METHODS

Patients with colorectal or anal cancer that received first-time treatment with 5-FU-based chemotherapy were prospectively included. Holter recording, clinical evaluation, 12-lead electrocardiogram, and assessment of plasma concentrations of troponin I and copeptin were performed before (control) and during 5-FU treatment (intervention).

RESULTS

A total of 108 patients were included, 82 with colorectal and 26 with anal cancer. The proportion of patients with myocardial ischemia on Holter recording was significantly higher during the first 5-FU infusion (14.1%) than before (3.7%; p = .001). The ischemic burden per day (p = .001), the number of ST depression episodes per day (p = .003), and the total duration of ischemic episodes per day (p = .003) were higher during the first 5-FU infusion than before, as was plasma copeptin (p < .001), whereas plasma troponin I was similar (p > 0.999). Six patients (5.6%) developed acute coronary syndromes and two (1.8%) developed symptomatic arrhythmias during 5-FU treatment.

CONCLUSION

5-FU infusion is associated with an increase in the number of patients with myocardial ischemia on Holter recording. According to biomarker analyses, 5-FU is associated with an increase in copeptin, but rarely with increases in cardiac troponin I. However, 5%-6% of the patients developed acute coronary syndromes during treatment with 5-FU.

IMPLICATIONS FOR PRACTICE

Symptomatic 5-fluorouracil (5-FU) cardiotoxicity occurs in 0.6%-19% of patients treated with this drug, but a small electrocardiographic (Holter) study has revealed silent myocardial ischemia in asymptomatic patients, suggesting a more prevalent subclinical cardiac influence. This study demonstrated a significant increase in the number of patients with myocardial ischemia on Holter recording during 5-FU treatment and an increase in ischemic burden. Cardiac biomarker analyses suggested that 5-FU infusion results in endogenous stress (increased copeptin) but rarely induces myocyte injury (no change in troponin). These findings suggest a more prevalent cardiac influence from 5-FU and that Holter recording is an important tool in the evaluation of patients with suspected cardiotoxicity from 5-FU.

Risk Stratification and in Hospital Morality in Patients Presenting with Acute Coronary Syndrome (ACS) in Bahrain

Background:

Risk factors and short-term mortality in patients presented with Acute Coronary Syndrome (ACS) in Bahrain has not been evaluated before.

Aim:

In this prospective observational study, we aim to determine the clinical risk profiles of patients with ACS in Bahrain and describe the incidence, pattern of presentation and predictors of in-hospital clinical outcomes after admission.

Methods:

Patients with ACS were prospectively enrolled over a 12 month period. The rate of incidence of risk factors in patients was compared with 635 non-cardiac patient admissions that matched for age and gender. Multiple logistic regression analysis was used to predict poor outcomes in patients with ACS. The variables were ages >65 years, body mass index (BMI) >28 kg/m², GRACE (Global Registry of Acute Coronary Events) score >170, history of diabetes mellitus (DM), systolic hypertension >180 mmHg, level of creatinine >160 μmol/l and Heart Rate (HR) on admission >90 bpm, serum troponin rise and ST segment elevation on the ECG.

Results:

Patients with ACS (n=635) were enrolled consecutively. Mean age was 61.3 ± 13.2 years, with 417 (65.6%) male. Mean age for patients with ST-segment elevation myocardial infarction (STEMI, n=156) compared with non-STEMI (NSTEMI, n=158) and unstable angina (UA, n=321) was 56.5± 12.8 vs 62.5±14.0 years respectively. In-hospital mortality was 5.1%, 3.1% and 2.5% for patients with STEMI, NSTEMI, and UA, respectively. In STEMI patients, thrombolytic therapy was performed in 88 (56.5%) patients and 68 (43.5%) had primary coronary angioplasty (PCI). The predictive value of different clinical variables for in-hospital mortality and cardiac events in the study were: 2.8 for GRACE score >170, 3.1 for DM, 2.2 for SBP >180 mmHg, 1.4 for age >65 years, 1.8 for BMI >28, 1.7 for creatinine >160 μmol/L, 2.1 for HR >90 bpm, 2.2 for positive serum troponin and 2.3 for ST elevation.

Conclusion:

Patients with STEMI compared with NSTEMI and UA were of younger age. There was higher in-hospital mortality in STEMI compared with NSTEMI and UA patients. The most significant predictors of death or cardiac events on admission in ACS were DM, GRACE Score >170, systolic hypertension >180 mmHg, positive serum troponin and HR >90 bpm.

[Current strategies in the treatment of ventricular tachycardia by catheter ablation : A review]

The treatment of ventricular tachycardia has recently undergone relevant changes as certain interventional treatment options, such as radiofrequency catheter ablation, have gained in importance. Numerous current publications have demonstrated the advantages of catheter ablation compared to conventional therapy with antiarrhythmic drugs in terms of effectiveness and morbidity. Improving the ablation technique and identifying those patient collectives who are most likely to benefit from ablation are still the objectives of current research. The treatment of ventricular tachycardia in the setting of different cardiac and non-cardiac conditions can be challenging and requires understanding of the current procedures and the recommendations for catheter ablation of ventricular tachycardia. This review succinctly summarizes the current research in this evolving field of interventional cardiology.

Post-Resuscitation ECG for Selection of Patients for Immediate Coronary Angiography in Out-of-Hospital Cardiac Arrest

BACKGROUND

We aimed to investigate coronary angiographic findings in unselected out-of-hospital cardiac arrest patients referred to immediate coronary angiography (ICA) irrespective of their first postresuscitation ECG and to determine whether this ECG is useful to select patients with no need of ICA.

METHODS AND RESULTS

All resuscitated patients admitted after out-of-hospital cardiac arrest without a clear noncardiac cause underwent ICA. Patients were retrospectively grouped according to the postresuscitation ECG blinded for ICA results: (1) ST elevation or presumably new left bundle branch block, (2) other ECG signs indicating myocardial ischemia, and (3) no ECG signs indicating myocardial ischemia. All coronary angiograms were reevaluated blinded for postresuscitation ECGs. Two hundred and ten patients were included with mean age 62±12 years. Six-months survival with good neurological outcome was 54%. Reduced Thrombolysis in Myocardial Infarction flow (0-2) was found in 55%, 34%, and 18% and a ≥90% coronary stenosis was present in 25%, 27%, and 19% of patients in group 1, 2, and 3, respectively. An acute coronary occlusion was found in 11% of patients in group 3. ST elevation/left bundle branch block identified patients with reduced Thrombolysis in Myocardial Infarction (0-2) flow with 70% sensitivity and 62% specificity. Among patients with initial nonshockable rhythms (24%), 32% had significantly reduced Thrombolysis in Myocardial Infarction flow.

CONCLUSIONS

Initial ECG findings are not reliable in detecting patients with an indication for ICA after experiencing a cardiac arrest. Even in the absence of ECG changes indicating myocardial ischemia, an acute culprit lesion may be present and patients may benefit from emergent revascularization. CLINICAL TRIAL REGISTRATIONURL: http://www.clinicaltrials.gov. Unique identifier: NCT01239420.

New insights into the management of rhythm and conduction disorders after acute myocardial infarction

PATIENT

Male, 53 FINAL DIAGNOSIS: Myocardial infarction Symptoms: Chest pain • tachycardia

MEDICATION

- Clinical Procedure: - Specialty: Cardiology.

OBJECTIVE

Challenging differential diagnosis.

BACKGROUND

Comorbidities, including obesity and sleep-breathing disorders, can adversely influence outcomes in acute myocardial infarction (AMI), and should be considered in diagnosis and treatment administration.

CASE REPORT

The case demonstrates the difficulties of treating a middle-aged Caucasian patient with multiple comorbidities that could be overcome by a personalized approach and evaluation of concomitant sleep-breathing disorders (by polysomnography study). Diagnosis and treatment of sleep apnea by positive airway pressure (PAP therapy) played a pivotal role in heart rate and rhythm control.

CONCLUSIONS

In this case, effective PAP therapy enabled titration of antiarrhythmic drugs (to maximal doses) to achieve heart rate control and to eliminate severe ventricular tachyarrhythmias and contributed to the better recovery in a post-AMI patient with left ventricular systolic dysfunction.

Tools for risk stratification of sudden cardiac death: a review of the literature in different patient populations

While various modalities to determine risk of sudden cardiac death (SCD) have been reported in clinical studies, currently reduced left ventricular ejection fraction remains the cornerstone of SCD risk stratification. However, the absolute burden of SCD is greatest amongst populations without known cardiac disease. In this review, we summarize the evidence behind current guidelines for implantable cardioverter defibrillator (ICD) use for the prevention of SCD in patients with ischemic heart disease (IHD). We also evaluate the evidence for risk stratification tools beyond clinical guidelines in the general population, patients with IHD, and patients with other known or suspected medical conditions.

Nonsustained ventricular tachycardia

Nonsustained ventricular tachycardia (NSVT) has been recorded in a wide range of conditions, from apparently healthy individuals to patients with significant heart disease. In the absence of heart disease, the prognostic significance of NSVT is debatable. When detected during exercise, and especially at recovery, NSVT indicates increased cardiovascular mortality within the next decades. In trained athletes, NSVT is considered benign when suppressed by exercise. In patients with non-ST-segment elevation acute coronary syndrome, NSVT occurring beyond 48 h after admission indicates an increased risk of cardiac and sudden death, especially when associated with myocardial ischemia. In acute myocardial infarction, in-hospital NSVT has an adverse prognostic significance when detected beyond the first 13 to 24 h. In patients with prior myocardial infarction treated with reperfusion and beta-blockers, NSVT is not an independent predictor of long-term mortality when other covariates such as left ventricular ejection fraction are taken into account. In patients with hypertrophic cardiomyopathy, and most probably genetic channelopathies, NSVT carries prognostic significance, whereas its independent prognostic ability in ischemic heart failure and dilated cardiomyopathy has not been established. The management of patients with NSVT is aimed at treating the underlying heart disease.