Underdiagnosis of VT due to cycle length variation among cardiac sarcoidosis patients having ICD: Problem with stability discriminator.

BACKGROUND: Implantable cardioverter defibrillator (ICD) is recommended for patients with ventricular tachycardia (VT) due to cardiac sarcoidosis (CS). Programming supraventricular tachycardia (SVT) discriminators (onset, stability, and morphology/template match) is generally recommended to minimize inappropriate therapies. However, VT in patients with CS is known to show cycle length variability (CLV) and pleomorphism. OBJECTIVE: To determine whether the stability criterion, designed to prevent inappropriate therapy during atrial fibrillation with rapid ventricular rates, could potentially lead to incorrect classification of VT as SVT and inappropriately delay or inhibit ICD therapy. METHODS: Cases of biopsy-proven CS with VT were analyzed. For patients with implanted devices, all recorded electrograms of tachycardia episodes and ICD therapies were analyzed at last follow up. RESULTS: A total of 142 patients were included (mean age 38 years, 87 males). One hundred and three of 142 patients had implanted devices (ICD or CRT-D). Thirty eight of 103 (36.9%) patients received appropriate ICD therapies over 3 ± 2.2 years follow up. Four of 38 (10.5%) of patients experienced delayed-detection or underdetection of VT related to CLV, resulting in VT counters being repeatedly "reset" (classified as "unstable" rhythms). Retrospective analysis of other VT episodes in 70 of 103 (68%) patients revealed that 25 of 80 (31.3%) episodes had > 50 ms cycle length oscillations. CONCLUSION: Among CS patients with VT, CLV is a common occurrence seen in two-thirds of VT episodes. Routine programming of the stability criterion may result in underdetection of VT in a subset of such patients. We recommend that the stability criterion should be programmed "OFF" for patients with CS, unless the patient has documented atrial fibrillation.

Outflow-tract ventricular tachycardia: Can 12 lead ECG during sinus rhythm identify underlying cardiac sarcoidosis?

BACKGROUND: Patients with outflow tract ventricular tachycardia (OTVT) with normal echocardiogram are labeled as idiopathic VT (IVT). However, a subset of these patients is subsequently diagnosed with underlying cardiac sarcoidosis (CS). OBJECTIVE: Whether electrocardiogram (ECG) abnormalities in sinus rhythm (SR) can differentiate underlying CS from IVT. METHODS: We retrospectively analyzed the SR-ECGs of 42 patients with OTVT/premature ventricular complexes (PVC) and normal echocardiography. All underwent advanced imaging with cardiac magnetic resonance (CMR)/18FDG PET-CT for screening of CS. Twenty-two patients had significant abnormalities in cardiac imaging and subsequently had biopsy-proven CS (Cases). Twenty patients had normal imaging and were categorized as IVT (Controls). SR-ECGs of all patients were analyzed by 2 independent, blinded observers. RESULTS: Baseline characteristics were comparable. Among the ECG features analyzed - fascicular (FB) or bundle branch block (BBB) was seen in 9/22 Cases vs. 1/20 controls (p = 0.01). Among patients without FB or BBB, fragmented QRS (fQRS) was present in 9/13 cases but in none of the controls (p < 0.001). Low voltage QRS was more often seen among cases as compared to controls (10/22 vs. 3/20 p = 0.03). A stepwise algorithm based on these 3 sets of ECG findings helped to diagnose CS among patients presenting with OTVT/PVC with sensitivity of 91%, specificity of 75%, a PPV of 80%, and a NPV of 88%. CONCLUSIONS: In patients presenting with OTVT/PVC: FB/BBB, fQRS, and low QRS voltage on the baseline ECG were more often observed among patients with underlying CS as compared to true IVT. These findings may help to distinguish underlying CS among Cases presenting with OTVT/PVC.

Severe left ventricular systolic dysfunction after permanent pacemaker implantation: Should we pause before upgrading to biventricular pacing?

Left ventricular (LV) systolic dysfunction leading to heart failure (HF) is known to occur after permanent pacemaker implantation (PPI) in a subset of patients. They are often treated by upgradation of the pacemaker to cardiac resynchronisation therapy (CRT). We report a case of progressive LV dysfunction and HF after PPI. Cardiac 18FDG-PET-CT scan revealed abnormal myocardial FDG uptake suggestive of cardiac sarcoidosis (CS). Biopsy from FDG avid lymph node demonstrated non-caseating granuloma. Therapy with steroids resulted in resolution of HF symptoms accompanied by a significant improvement in LV function.

Tailored approach for management of ventricular tachycardia in cardiac sarcoidosis.

INTRODUCTION: Treating ventricular tachycardia (VT) in patients with cardiac sarcoidosis (CS) is challenging as patients present in different phase of the disease (inflammatory, scar, or sometimes both). A  customized approach to treatment is required for better outcomes. We describe our experience in the management of VT in CS based on the phase of the disease. METHODS AND RESULTS: Patients were considered to have myocardial inflammation if there was an increased myocardial 18 fluorodeoxy glucose (FDG) uptake in PET-CT scan of the chest (n = 14). These patients were treated with antiarrhythmic drugs (AADs) and immunosuppression. Patients with scar related VT (without active inflammation) were managed with AADs and underwent radiofrequency ablation (RFA) if unresponsive to drug therapy (n = 4). Patients previously treated for CS who presented with VT and evidence of reactivation (abnormal FDG uptake) after a quiescent period of 6 months were treated with intensified immunosuppression alongside AADs (n = 3/14). Patients with myocardial inflammation responded well to immunosuppression. Patients with drug resistant VT in the scar phase responded well to RFA. Four patients in the inflammatory group had recurrence of VT during follow-up of whom 3 were found to have disease reactivation. Intensified immunosuppression suppressed VT in all 3 patients. In 1 patient, VT recurrence was found to be scar related and required RFA for control. CONCLUSION: Tailoring therapy for VT in CS according to the phase of disease results in good clinical outcome and avoids unnecessary immunosuppression.

Use of a novel pacing mode to achieve biventricular pacing in a patient with recurrent atrial lead dislodgement after CRT-D implantation.

Cardiac resynchronization therapy device (CRT-P and CRT-D) implantation has increased tremendously with increasing operator experience, eligible patients and expansion of indications. Refinements in devices and algorithms now aid physicians to improve biventricular pacing and optimize CRT. We report a case in which an interesting device program was used to achieve biventricular pacing after repeated dislodgement of the atrial lead in a patient implanted with CRT-D.

Permanent HIS bundle Pacing Feasibility in Routine Clinical Practice: Experience from an Indian Center.

There is a paucity of experience regarding His bundle pacing (HBP) at laboratories initially attempting the procedure, especially in the Indian scenario. Patient who underwent HBP were selected for pacing therapy or in lieu of cardiac resynchronization therapy (CRT) at a single center. Among 22 patients attempted, 19 patients underwent successful implant, achieving selective HBP in 14 patients. There was a significant improvement in left ventricular ejection fraction (LVEF) (49.3 ± 9.3 vs. 36.7 ± 9.2) in the LV dysfunction subgroup (n = 6). Over a follow-up of 15 ± 6.5 months, thresholds were stable in all except one patient, and there was no requirement of lead revision. In summary, we found that HBP is a feasible option for achieving physiological pacing.

Prognostic value of fluorine-18 fluoro-2-deoxyglucose positron emission computed tomography in patients with unexplained atrioventricular block.

BACKGROUND: The cause of atrioventricular conduction block (AVB) remains unexplained in a significant number of patients. Granulomatous myocarditis is an uncommon but important cause of AVB. Fluorine-18 fluoro-2-deoxyglucose positron emission computed tomography (18-FDG PET) scan has emerged as a sensitive tool for diagnosing granulomatous myocarditis. OBJECTIVE: The purpose of this study was to evaluate the prognostic value of 18-FDG PET scan in patients with unexplained AVB. METHODS: Patients age 18-55 years presenting with unexplained AVB and requiring a permanent pacemaker were evaluated with a fasting 18-FDG PET scan. Transthoracic echocardiography was performed at baseline and at follow-up. Major adverse cardiac events (ventricular tachycardia, heart failure, cardiac death) were noted during follow-up. RESULTS: Over a period of 3 years, 35 patients (20 females, 15 males; mean age 43.67 ± 11.21 years) were included in the study. Abnormal myocardial FDG uptake was noted in 15 patients (42.8%). Four patients consented for biopsy of paracardiac FDG avid lymph nodes, which revealed granulomatous inflammation (one of which grew Mycobacterium tuberculosis in culture). Mean follow-up period was 24 months. Major adverse cardiac events were significantly higher in the patients with abnormal PET uptake (P < .01) compared to those with normal scans. CONCLUSION: Patients with high-degree AVB and abnormal myocardial 18-FDG PET uptake have more adverse cardiac events and worse outcomes. Early screening for myocardial inflammation and appropriate treatment may prevent these complications. Tuberculosis may be an important cause of unexplained AVB, apart from sarcoidosis, in developing countries such as India.

Safety and efficacy of epicardial approach to catheter ablation of ventricular tachycardia - An institutional experience.

BACKGROUND AND AIM: Epicardial approach to VT ablation increases the success rate of ablation but is not without complications. We studied the safety and efficacy of epicardial VT ablations performed at our institute. METHODS: All patients who underwent epicardial VT ablation at our institute were studied retrospectively. The outcome of VT ablation was among three groups: ischaemic cardiomyopathy (ICM), non-ischaemic cardiomyopathy (NICM) and granulomatous myocarditis (GM). Safety outcomes assessed included all complications considered to be due to pericardial access or epicardial mapping/ablation. RESULTS: A total of 54 patients (total 119 VTs, mean 2.2 (0.9)) were taken up for ablation procedure through epicardial access. Mean age: 47 (10) years, males: 83%. All patients had drug resistant recurrent VTs. The epicardial procedure was abandoned in three patients due to access issues; percutaneous sub-xiphoid access was employed in 48 and surgical approach in four patients. Complete success was achieved in 59% and partial success in 76%. The outcomes were poor in ICM patients as compared to those with GM and NICM. Overall success rates for all clinical VTs were 89% in GM, 90% in NICM and 67% in ICM. Success rates for epicardial VT ablation were 94%, 85% and 78% respectively for GM, NICM and ICM. Procedure related complications occurred in six patients. CONCLUSION: Epicardial ablation for VT offers good immediate outcomes with acceptable safety profile.

Twisting wire technique: An effective method to retrieve fractured guide wire fragments from coronary arteries.

With the increasing number of complex coronary interventions, there has been an increase in the incidence of device fractures and dislodgements. We report 2 cases of successful retrieval of fractured guide wire fragments from coronary arteries using the twisting wire technique and discuss its advantages and issues.

Acute stent thrombosis due to stent underexpansion managed with rotational atherectomy.

Stent underexpansion is a well known risk factor for stent thrombosis. We report a case of acute stent thrombosis which occurred after primary percutaneous coronary intervention to the right coronary artery for an inferior ST-elevation myocardial infarction. Minutes after completion of the procedure, the patient had acute stent thrombosis, manifested by new chest pain and new ST-elevation. IVUS showed the stent to be underexpanded. Despite high pressure balloon inflation, the stent remained underexpanded. This was then managed with rotational atherectomy within the underexpanded stent, followed by high-pressure balloon dilatation and deployment of another stent within it.

Percutaneous mitral commissurotomy in rheumatic mitral stenosis associated with cor triatriatum.

Cor triatriatum is an uncommon congenital anomaly and its coexistence with rheumatic mitral stenosis is rare. We report two patients with rheumatic mitral stenosis with associated cor triatriatum. Percutaneous mitral valvuloplasty was successfully performed in both cases. We describe the clinical presentation and discuss the technical issues related to balloon mitral valvotomy in these cases.

Giant aneurysm of left main coronary artery.

We report a case of giant aneurysm of left main coronary artery in a patient with coronary artery disease (CAD).

Coronary stenting in a patient with single coronary artery and double-vessel disease!

A 52-year-old female with exertional angina of class II severity was referred to us. Her coronary angiogram revealed an anomalous single coronary artery from left coronary sinus. Its circumflex branch continued in the right AV groove to supply the right coronary artery territory. Significant stenoses were found in the left anterior descending and circumflex arteries. In view of her persistent angina despite optimal antianginals, percutaneous intervention of the stenosed arteries was done, after which the symptoms abated. Single coronary artery is a rare coronary anomaly, with reported prevalence of 0.024%-0.066%. It is usually asymptomatic. Coronary angioplasty of such rare anomalous vessels for atherosclerotic disease has been reported previously. We describe stenting of both the major branches of an anomalous single coronary artery in a patient with atherosclerotic coronary artery disease with a brief review and discuss the issues with intervention on single coronary artery.

Significance of the intima-media thickness of carotid and thoracic aorta in coronary artery disease in the South Indian population.

BACKGROUND: Ultrasound detected intima-media thickness (IMT) of the carotid artery and thoracic aorta are possible screening tests to assess the risk of coronary artery disease (CAD) in asymptomatic individuals. OBJECTIVE: Aim of the study was to assess the utility of carotid and aortic IMT as a predictor of CAD and to assess the extent of IMT with severity of CAD in a South Indian population. PATIENTS AND METHODS: A cross-sectional and analytical study was carried out among 40 cases, who had angiographic evidence of CAD against 30 healthy control subjects with a normal treadmill test. At plaque-free regions, the carotid IMT was evaluated by B-mode ultrasonography and thoracic aorta IMT was evaluated by trans-esophageal echocardiography (TEE). The significance of difference in means between two groups was analyzed using one-way ANOVA F-test and the significance of difference in proportions by Chi-square test. Multiple comparisons were done by Bonferroni t test. The correlation between IMT and severity of CAD was assessed by Spearman's method. RESULTS: There were 38 males and 2 females among cases with age 51.7 ± 8.3 years, and 28 males and 2 females among control subjects with age 52.2 ± 7.1 years. Increased carotid IMT was noted among 24 cases and 2 control subjects, and the association was significant for CAD [P < 0.001, Chi-square = 20.89, odds ratio (OR) = 21.00, and 95% confidence interval (CI) = 4.78-89.59]. Similarly, 19 cases and one control subject had abnormal IMT with positive correlation for CAD (P < 0.001, Chi-square = 16.39, OR = 28.24, and 95% CI = 4.06-163.21). There was no association between IMT and diabetes, hypertension, or smoking; however, IMT was significantly associated with age and dyslipidemia. Also, there was no correlation between extent of IMT and severity of CAD. CONCLUSIONS: IMT of the carotid and thoracic aorta is strongly associated with risk of CAD in a South Indian population, and may be used as a non-invasive screening tool for coronary atherosclerosis in resource-limited settings. The presence of dyslipidemia influenced IMT and may be used as a tool to follow patients on hypolipidemic drugs.