Effect of left ventricular aneurysm on risk of sudden and nonsudden cardiac death

Frequency, predictors and cardiovascular outcomes associated with transthoracic echocardiographic findings during acute ischaemic stroke hospitalisation

OBJECTIVE

To characterise the clinical utility of transthoracic echocardiography (TTE) at the time of acute ischaemic stroke (AIS).

BACKGROUND

The utility of obtaining a TTE during AIS hospitalisation is uncertain.

METHODS

We studied AIS hospitalisations at a single centre (2002-2016). TTE abnormalities were classified as findings associated with: high stroke risk (Category I), cardiac events (Category II) and of unclear significance (Category III). We performed logistic regressions to predict Category I, II and III abnormalities. The odds of 1 year recurrent stroke hospitalisation captured by ICD 9 and 10 codes as a function of Category I, II and III abnormalities were assessed. Improvement in predictive capacity for 1 year recurrent ischaemic stroke hospitalisation beyond stroke risk factors was evaluated by net reclassification improvement.

RESULTS

There were 5523 AIS hospitalisations. Nearly 81% of admission TTEs were abnormal (18.7% Category I, 32.7% Category II, 72.8% Category III). Older patients with coronary artery disease, atrial fibrillation, hypertension, diabetes, and patent intracranial and extracranial vessels were likely to have an abnormal TTE. Category I finding was associated with lower odds of 1-year recurrent stroke hospitalisation (OR 0.54, 95% CI 0.30 to 0.96). Category I data significantly improved the predictive value for 1-year recurrent ischaemic stroke hospitalisation beyond stroke risk factors (net reclassification improvement 0.1563, 95% CI 0.0465 to 0.2661).

CONCLUSIONS

TTE abnormalities associated with stroke and cardiac event risk were commonly detected during AIS hospitalisation. Detection of Category I TTE findings reduced the risk of recurrent stroke, potentially due to neutralisation of the cardioembolic source by targeted therapy, indicating the clinical utility of TTE.

Non-arrhythmic causes of sudden death: A comprehensive review

Sudden cardiac death (SCD) is a major public health issue in the United States and worldwide. It is estimated to affect between 1 and 1.5 million patients worldwide annually, with the global burden expected to rise due to the concomitant rise in coronary artery disease in the developing world. Although arrhythmic causes of SCD such as ventricular tachycardia and ventricular fibrillation are common and well-studied, non-arrhythmic causes are also important, with diverse etiologies from ischemia-related structural heart disease to non-ischemic heart diseases, non-atherosclerotic coronary pathologies, and inflammatory states. Recent research has also found that risk factors and/or demographics predispose certain individuals to a higher risk of non-arrhythmia-related SCD. This review discusses the epidemiology, mechanisms, etiologies, and management of non-arrhythmic SCD.

Surgical treatment for endocardial radiofrequency ablation-resistant sustained monomorphic ventricular tachycardia with mural thrombus including dense calcification in the left ventricle

Catheter ablation provides effective results for sustained monomorphic ventricular tachycardia (VT), but the presence of mural thrombus including dense calcification occasionally causes unfavorable outcomes. The case of a 67-year-old man in whom sustained monomorphic VT, which was resistant to endocardial radiofrequency ablation, in the presence of mural thrombus including dense calcification after coronary artery bypass grafting was successfully treated by left ventricular reconstruction with cryoablation is reported.

Pathophysiology of Myocardial Infarction

Myocardial infarction is defined as sudden ischemic death of myocardial tissue. In the clinical context, myocardial infarction is usually due to thrombotic occlusion of a coronary vessel caused by rupture of a vulnerable plaque. Ischemia induces profound metabolic and ionic perturbations in the affected myocardium and causes rapid depression of systolic function. Prolonged myocardial ischemia activates a "wavefront" of cardiomyocyte death that extends from the subendocardium to the subepicardium. Mitochondrial alterations are prominently involved in apoptosis and necrosis of cardiomyocytes in the infarcted heart. The adult mammalian heart has negligible regenerative capacity, thus the infarcted myocardium heals through formation of a scar. Infarct healing is dependent on an inflammatory cascade, triggered by alarmins released by dying cells. Clearance of dead cells and matrix debris by infiltrating phagocytes activates anti-inflammatory pathways leading to suppression of cytokine and chemokine signaling. Activation of the renin-angiotensin-aldosterone system and release of transforming growth factor-β induce conversion of fibroblasts into myofibroblasts, promoting deposition of extracellular matrix proteins. Infarct healing is intertwined with geometric remodeling of the chamber, characterized by dilation, hypertrophy of viable segments, and progressive dysfunction. This review manuscript describes the molecular signals and cellular effectors implicated in injury, repair, and remodeling of the infarcted heart, the mechanistic basis of the most common complications associated with myocardial infarction, and the pathophysiologic effects of established treatment strategies. Moreover, we discuss the implications of pathophysiological insights in design and implementation of new promising therapeutic approaches for patients with myocardial infarction.

Endovascular catheter ablation of ventricular tachycardia in a patient with a surgically repaired congenital left ventricular aneurysm

We present a patient with a congenital left ventricular aneurysm who visited our outpatient clinic for a routine check-up and, during this visit, lost consciousness due to sustained ventricular tachycardia. In our patient, endocardial mapping revealed extensive conduction abnormalities, and successful ablation was accomplished at the endocardial surface.

Surgery for Ventricular Tachycardia in Patients Undergoing Left Ventricular Reconstruction by the Dor Procedure

BACKGROUND

Surgical ventricular restoration (the Dor procedure) is an option in patients with coronary artery disease and postinfarction left ventricular aneurysm. The procedure can be extended to treat ventricular tachycardia (VT). The aim of this study was to evaluate the Dor procedure including VT surgery in our institution.

METHODS

From July 1997 to December 2003, 53 consecutive patients with left ventricular aneurysm and VT underwent surgical ventricular restoration including nonguided endocardiectomy and cryoablation. Twenty-four patients had at least one preoperative episode of spontaneous VT, of which 8 were survivors of sudden cardiac death. Twenty-nine patients had inducible-only VT. In 45 patients, who underwent preoperative programmed stimulation, sustained uniform VT could be initiated. Arrhythmia control was evaluated by programmed stimulation or analysis of events registered by implanted defibrillators and by review of patient's records.

RESULTS

Early mortality was 2 of 53 (3.8%). Mean follow-up was 3.7 years. At 1, 3, and 5 years overall actuarial survival was 94%, 80%, and 59%, respectively. Surgical success rate in patients with preoperative spontaneous VT was 91%. Inducible VT was found in 5 of 35 patients who underwent postoperative programmed stimulation. There was no arrhythmia-related late death and there was no loss to follow-up.

CONCLUSIONS

The Dor procedure including VT surgery is an effective treatment for postinfarction left ventricular aneurysm and VT and eliminates the need for an implantable defibrillator in most patients. Early and long-term results are good in terms of survival and arrhythmia control.

Diagnosis of ventricular aneurysm and other severe segmental left ventricular dysfunction consequent to a myocardial infarction in the presence of right bundle branch block: ECG correlates of a positive diagnosis made via echocardiography and/or contrast ventriculography

BACKGROUND

A diagnostic ECG sign of a ventricular aneurysm (VA) consequent to a myocardial infarction (MI) in the presence of complete left bundle branch block was recently described, and consists of the presence of ST-segment elevation (+ST), instead of the expected ST-segment depression (-ST), in leads V4-6. Generally, complete right bundle branch block (RBBB) is associated with -ST in ECG leads V1-3. We hypothesized that stable +ST, instead of the expected -ST in leads V1-3 in patients with RBBB could be also diagnostic of a VA and other severe segmental left ventricular dysfunction (VA/SSD). Thus, this study was performed to explore the feasibility of using the ECG to diagnose a VA/SSD in the presence of RBBB, and to evaluate the determinants of such diagnosis.

METHODS

The frequency of +ST > or =1 mm in leads V1-3 was assessed in patients with RBBB, prior MI, and a VA/SSD diagnosed by echocardiography and/or contrast left cine-ventriculography. The ECG correlates for a positive or negative diagnosis of a VA/SSD were explored.

RESULTS

Out of 4197 files of our cohort of the Cardiology Clinic, RBBB was detected in 175 patients. Of these, 28 had an old MI, and had a VA/SSD diagnosed by > or =1 of noninvasive and/or invasive non-ECG tests. Twenty-one of these 28 patients had stable +ST in > or =1 of leads V1-3 (Group 1), and 7 did not (Group 2). Thus, the sensitivity of this ECG criterion for the diagnosis of VA/SSD was 75%, and the specificity was 100% in this highly selective group. VA/SSD in the septal and anterior myocardial regions was more frequent in the patients of Group 1, than in the patients of Group 2 (P = 0.03 and 0.02, correspondingly). The number of myocardial territories involved with the VA/SSD, or the ejection fraction were not different in the two groups (P = 0.65 and 0.55, correspondingly).

CONCLUSION

VA/SSD can be diagnosed in the presence of RBBB by the concordant to the QRS repolarization changes (+ST) in leads V1-3. Positivity of this ECG marker for VA/SSD correlates with involvement of the septal or anterior myocardial regions, and represents mechanistically a superimposition of primary repolarization alterations, overcoming the secondary such changes.

Gender differences in ventricular arrhythmia recurrence in patients with coronary artery disease and implantable cardioverter-defibrillators

OBJECTIVES

We sought to determine whether men and women with coronary artery disease (CAD) and implantable cardioverter-defibrillators (ICDs) differ in frequency of arrhythmia recurrence and whether gender differences are independent of clinical, electrocardiographic, and electrophysiologic characteristics.

BACKGROUND

Epidemiologic studies show that women have a lower rate of sudden cardiac death (SCD) than men, even among patients with CAD. Whether this is due to differing susceptibilities to ischemia or to arrhythmia is unknown.

METHODS

The clinical records and ICD data disks of 340 men and 59 women with CAD who received an ICD between June 1990 and June 2000 were reviewed. Ventricular tachycardia (VT) or ventricular fibrillation (VF) recurrences were compared between genders and relationship with other factors was analyzed.

RESULTS

Sustained VT/VF occurred in 52% of men and 34% of women (p < 0.01). Men experienced more total VT/VF events (p < 0.01), more shock-treated VT/VF events (p < 0.03), more electrical storms (p < 0.001), and had VT/VF on more days in follow-up (p < 0.01). Gender differences were independent of measured clinical, electrocardiographic, and electrophysiologic factors. In stratified analyses, the gender differences in VT/VF recurrence were greatest in patients presenting with sustained monomorphic VT and those with inducible VT at electrophysiology study.

CONCLUSIONS

Women were less likely to experience VT/VF, and had fewer VT/VF episodes, than men. These findings were strongest in patients with evidence of a stable anatomic VT circuit: those with clinical or electrophysiologically induced VT. This study suggests that differing susceptibility to arrhythmia triggering may underlie the known differences in SCD rates between men and women.

Normokinesia adjacent to left ventricular aneurysm: a differential risk for sudden cardiac death

BACKGROUND

Following myocardial infarction, the ejection fraction (EF) is an indiscriminate predictor of both non-sudden cardiac death (NSCD) and sudden cardiac death (SCD). However, development of a left ventricular aneurysm (LVA) confers independent risk only for SCD. Thus, we tested the hypothesis that mechanical factors, other than the global left ventricular performance, are causally related to SCD in the presence of LVA.

METHODS

A secondary analysis was conducted from a longitudinal, prospective, long-term follow-up cohort study of 66 patients with LVA (diastolic eccentricity and systolic dyskinesia) diagnosed by ventriculography. The left ventricular contour was divided into five segments and contractility scores for the residual myocardium and the segments adjacent to the aneurysm were allocated along with assessment of the EF. A normal adjacent segment was considered present when at least one segment adjacent to the aneurysm exhibited normokinesia. Presence of ventricular tachycardia was documented by Holter recording.

RESULTS

At a 5.2-year median follow-up, there were 12 NSCD and 8 SCD. The EF was lower among patients who died vs. survivors (31.5% vs. 39.7%, P=0.01). Patients with NSCD and SCD, exhibited similar EF but disparate residual contractility scores (3.0 vs. 4.1, P<0.004). Among cardiac deaths, a decreasing residual contractility score differentially predicted NSCD (odds ratio=17.06, P<0.03), while a normokinetic adjacent segment differentially predicted SCD (odds ratio=21, P<0.02). Albeit a predictor of both NSCD and SCD, ventricular tachycardia increased markedly the model significance (P<0.004) only when tested with a normokinetic adjacent segment vis-a'-vis SCD.

CONCLUSIONS

In the presence of LVA, the contractility of the non-aneurysmal myocardium is a differential predictor of death from pump failure. In contrast, a normal segment adjacent to LVA constitutes an independent and discriminate predictor of SCD, possibly through an arrhythmic substrate linked to the motion discordance between the expanding aneurysm and a normokinetic adjacent myocardium.

Diagnosis of myocardial infarction-induced ventricular aneurysm in the presence of complete left bundle branch block

An analysis of the 4,196 files of our Cardiology Clinic cohort showed 128 patients with a complete left bundle branch block (LBBB) in their electrocardiograms (ECGs). Of these patients, 27 had suffered a myocardial infarction in the past and had been found to have a ventricular aneurysm (VA), documented by > or = 1 of several noninvasive and invasive diagnostic methods. Five of these 27 patients had stable ST-segment elevation in > or = 1 of left precordial ECG leads, with predominantly positive QRS complexes (an ECG criterion for the diagnosis of VA in the presence of LBBB, which we have recently described). The sensitivity of this ECG criterion for the diagnosis of VA was 18.5%, and the specificity was 100%. The frequency of distribution of VA in the septal, and even more, apical myocardial regions was higher in the patients with a positive ECG diagnosis of VA, than in the patients with a negative one (P = .049, and P = .009, correspondingly). The number of myocardial territories involved with a VA was not different in the 2 subgroups (P =.325). Pathophysiologically, this ECG alteration diagnostic of VA represents a superimposition of the primary ST-segment elevation due to the VA, on the expected secondary ST-segment depression due to the LBBB, and represents a summation effect.

Outcome of left ventricular aneurysmectomy with patch repair in patients with severely depressed pump function

To determine the efficacy of left ventricular (LV) aneurysm resection and endoventricular patch repair with septal exclusion in patients with severely depressed pump function, we retrospectively selected 62 patients (mean age 59 +/- 7 years) with preoperative LV ejection fraction < or = 20%, from a series of 322 patients with postinfarction LV aneurysm who underwent this type of surgery at our center during a 5-year period. Mean ejection fraction was 17 +/- 3%; all patients were in New York Heart Association (NYHA) class III/IV, and all had hemodynamic and electrophysiologic studies before and after surgery. We analyzed both operative and long-term survival, and hemodynamic, electrophysiologic, and angiographic variables, as well as the symptomatic state after surgery. Follow-up was available in all patients (mean 23 +/- 14 months). Subtotal endocardiectomy and cryotherapy were associated in patients presenting with spontaneous or inducible ventricular arrhythmias (VA). Hospital mortality rate was 19.3%. Ejection fraction improved from 17 +/- 3% to 37 +/- 10% (p < 0.001); ventricular arrhythmias decreased significantly after surgery. Factors influencing early mortality at multivariate analysis were the presence of critical lesions on the circumflex artery and the duration of cardiopulmonary bypass. At 1-year control, a significant reduction in NYHA class was observed and no patient was in NYHA class IV. The improvement in ejection fraction was maintained (39 +/- 11%), as well as the reduction in inducible and spontaneous ventricular arrhythmias. There were 5 late deaths at follow-up, accounting for a late mortality of 10% at 5 years.

Nonsustained ventricular tachycardia: identification and management of high-risk patients

NSVT is common in normal persons and in patients with a variety of heart diseases. When present in patients with coronary artery disease, particularly after a recent myocardial infarction, it is associated with an increased risk of sudden and nonsudden cardiac death. However, its prognostic significance in patients with nonischemic heart disease, with the possible exception of hypertrophic cardiomyopathy, remains controversial. In patients with coronary artery disease, certain diagnostic tools (e.g., determination of left ventricular function. PVS) help to identify low- and high-risk patients who may or may not benefit from antiarrhythmic treatment. There is no consensus at this point as to the best approach for identifying and treating high-risk patients. Ongoing clinical trials should provide important information on the roles of signal-averaged ECGs and PVS in the management of patients with NSVT and coronary artery disease. In the meantime, treatment should be individualized for each patient. beta-Blockers should probably be the first line of therapy to control symptoms. Asymptomatic potentially high-risk patients (i.e., those with LVEF < 40%) should be referred for enrollment in randomized controlled studies.