Mycobacterium tuberculosis infection of an intralobar pulmonary sequestration.

Pulmonary sequestration is a rare bronchopulmonary foregut anomaly that occurs when a portion of the lung derives its blood supply from an aberrant vessel rather than the customary tracheobronchial supply. The sequestration can be classified as intralobar or extralobar. Most patients with intralobar sequestration are asymptomatic. Among symptomatic patients, presentations vary greatly, from fever, cough with expectoration, exertional dyspnea, pleuritic chest pain, and hemoptysis to eventual lung abscess or empyema. Contrast-enhanced computed tomography/computed tomography angiography is performed to determine the origin of the anomalous blood supply as well as the pathological manifestations involving the lobes. We present a patient with diagnosed intralobar sequestration who developed pulmonary tuberculosis of the sequestered lung tissue. The patient was successfully managed with long-term antitubercular therapy and left lower lobectomy with ligation of the anomalous vessel.

Value of the signal-averaged electrocardiogram in arrhythmogenic right ventricular cardiomyopathy/dysplasia.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited disease that causes structural and functional abnormalities of the right ventricle (RV). The presence of late potentials as assessed by the signal-averaged electrocardiogram (SAECG) is a minor task force criterion. OBJECTIVE: The purpose of this study was to examine the diagnostic and clinical value of the SAECG in a large population of genotyped ARVC/D probands. METHODS: We compared the SAECGs of 87 ARVC/D probands (age 37 ± 13 years, 47 males) diagnosed as affected or borderline by task force criteria without using the SAECG criterion with 103 control subjects. The association of SAECG abnormalities was also correlated with clinical presentation, surface ECG, ventricular tachycardia (VT) inducibility at electrophysiologic testing, implantable cardioverter-defibrillator therapy for VT, and RV abnormalities as assessed by cardiac magnetic resonance imaging (cMRI). RESULTS: Compared with controls, all three components of the SAECG were highly associated with the diagnosis of ARVC/D (P <.001). They include the filtered QRS duration (97.8 ± 8.7 ms vs 119.6 ± 23.8 ms), low-amplitude signal (24.4 ± 9.2 ms vs 46.2 ± 23.7 ms), and root mean square amplitude of the last 40 ms of the QRS (50.4 ± 26.9 µV vs 27.9 ± 36.3 µV). The sensitivity of using SAECG for diagnosis of ARVC/D was increased from 47% using the established 2 of 3 criteria (i.e., late potentials) to 69% by using a modified criterion of any 1 of 3 criteria, while maintaining a high specificity of 95%. Abnormal SAECG as defined by this modified criterion was associated with a dilated RV volume and decreased RV ejection fraction detected by cMRI (P <.05). SAECG abnormalities did not vary with clinical presentation or reliably predict spontaneous or inducible VT and had limited correlation with ECG findings. CONCLUSION: Using 1 of 3 SAECG criteria contributed to increased sensitivity and specificity for the diagnosis of ARVC/D. This finding is incorporated in the recent modification of the task force criteria.

Long-term outcome of leads and patients following robotic epicardial left ventricular lead placement for cardiac resynchronization therapy.

INTRODUCTION: In cardiac resynchronization therapy (CRT), positive clinical response and reverse remodeling have been reported using robotically assisted left ventricular (LV) epicardial lead placement. However, the long-term performance of epicardial leads and long-term outcome of patients who undergo CRT via robotic assistance are unknown. In addition, since the LV lead placement is more invasive than a transvenous procedure, it is important to identify patients at higher risk of complications. METHODS: We evaluated 78 consecutive patients (70 ± 11 years, 50 male) who underwent robotic epicardial LV lead placement. The short- (<12 months) and long-term (≥ 12 months) lead performance was determined through device interrogations. Mortality data were determined by contact with the patient's family and referring physicians and confirmed using the Social Security Death Index. RESULTS: All patients had successful lead placement and were discharged in stable condition. When compared to the time of implantation, there was a significant increase in pacing threshold (1.0 ± 0.5 vs 2.14 ± 1.2; P < 0.001) and decrease in lead impedance (1010 ± 240 Ω vs 491 ± 209 Ω; P < 0.001) at short-term follow-up. The pacing threshold (2.3 ± 1.2 vs 2.14 ± 1.2; P = 0.30) and lead impedance (451 ± 157 Ω vs 491 ± 209 Ω; P = 0.10) remained stable during long-term follow-up when compared to short-term values. At a follow-up of 44 ± 21 months, there were 20 deaths (26%). These patients were older (77 ± 7 vs 67 ± 11 years; P = 0.001) and had a lower ejection fraction (EF) (13 ± 7% vs 18 ± 9%; P = 0.02) than surviving patients. CONCLUSION: Robotically implanted epicardial LV leads for CRT perform well over short- and long-term follow-up. Older patients with a very low EF are at higher risk of death. The risks and benefits of this procedure should be carefully considered in these patients.

Pulmonary vein isolation alone in patients with persistent atrial fibrillation: an ablation strategy facilitated by antiarrhythmic drug induced reverse remodeling.

INTRODUCTION: Pulmonary vein isolation (PVI) alone has been thought to be insufficient in patients with persistent atrial fibrillation (PersAF). We hypothesized that preablation treatment of PersAF with a potent antiarrhythmic drug (AAD) would facilitate reverse atrial remodeling and result in high procedural efficacy after PVI alone. METHODS AND RESULTS: Seventy-one consecutive patients (59.4 ± 9.8 years) with PersAF and prior AAD failure were treated with oral dofetilide (768 ± 291 mcg/day) for a median of 85 days pre-PVI. P-wave duration (Pdur) on ECG was used to assess reverse atrial remodeling. Thirty-five patients with paroxysmal (P) AF not treated with an AAD served as controls. All patients underwent PVI alone; dofetilide was discontinued 1-3 mos postablation. In the PersAF patients, the Pdur decreased from 136.3 ± 21.7 ms (assessed postcardioversion on dofetilide) to 118.6 ± 20.4 ms (assessed immediately prior to PVI) (P < 0.001). In contrast, no change in Pdur (122.6 ± 11.5 ms vs. 121.3 ± 13.7 ms, P = NS) was observed in PAF patients. The 6 and 12 mos AAD-free response to ablation was 76% and 70%, respectively, in PersAF patients, similar to the 80% and 75%, response in PAF patients (P = NS). A decline in Pdur in response to dofetilide was the only predictor of long-term clinical response to PVI in patients with PersAF. CONCLUSIONS: Pre-treatment with AAD resulted in a decrease in Pdur suggesting reverse atrial electrical remodeling in PersAF patients. This may explain the excellent clinical outcomes using PVI alone, and may suggest an alternative ablation strategy for PersAF.

Cardiac Resynchronization Therapy and Atrial Fibrillation.

Cardiac resynchronization therapy (CRT) is an important advance for the treatment of end--stage heart failure (HF). About 15-50% of HF is complicated by atrial fibrillation (AF) and associated with worsened outcomes. Meta-analyses from observational studies suggest that patients with AF derive similar benefits to CRT as patients in sinus rhythm (SR). The presence of AF, however, may interfere with optimal delivery of CRT due to competition with biventricular (BiV) capture by conducted beats. Atrioventricular junction (AVJ) ablation with permanent pacing eliminates interference by conducted beats and provides complete BiV capture. Catheter ablation of AF is an alternative to antiarrhythmic drugs to maintain sinus rhythm in patients with AF and HF. Randomized trial comparing catheter ablation, AVJ ablation and pharmacologic therapy are needed.

Activation of the endogenous coagulation system in patients with atrial flutter: relationship to echocardiographic markers of thromboembolic risk.

BACKGROUND: Atrial thrombus formation in patients with atrial flutter raises concerns of stroke risk. We investigated patients with isthmus-dependent atrial flutter for coagulation abnormalities before and after cardioversion to sinus rhythm by catheter ablation, and evaluated the relationship of the abnormalities to the echocardiographic risk markers of stroke. METHODS AND RESULTS: Plasma samples were drawn prior to insertion of catheters, immediately after the procedure, and 24 hours afterwards. At baseline, coagulation abnormalities were found in 22 out of 25 patients (88%). von Willebrand factor antigen (vWF-Ag) and factor VIII:C were elevated in 17 patients (68%) and 15 patients (60%), respectively. At baseline, mean plasma levels of vWF-Ag (250.1 +/- 144.4%) and factor VIII:C (215.0 +/- 77.1%) were increased. Key markers of thrombin generation, thrombin-antithrombin III complex (TAT; 47.8 +/- 30.9 microg/L vs 14.5 +/- 13.8 microg/L; p < 0.05) and prothrombin fragments 1.2 (F1.2; 2.5 +/- 0.5 nmoL/L vs 1.2 +/- 1.0 nmoL/L) were significantly elevated in the presence of spontaneous echo contrast. Further, both markers of thrombin generation inversely correlated with left atrial appendage emptying velocity (r = -0.42 and -0.63, p < 0.05). Levels of TAT and F1.2 increased after conversion and ablation. CONCLUSIONS: Endothelial-dependent coagulation factors were enhanced in most patients with atrial flutter. Spontaneous echo contrast and decreased atrial contractility were associated with increased thrombin generation. After conversion and ablation, an increase in thrombin generation and fibrinolysis suggest a transient pro-thrombotic state.

Computational method to predict esophageal temperature elevations during pulmonary vein isolation.

BACKGROUND: The esophagus is in close proximity to the posterior wall of the left atrium, which renders it susceptible to thermal injury during radiofrequency (RF) ablation procedures for atrial fibrillation (AF). Real-time assessment of esophageal position and temperature (T°) during pulmonary vein (PV) isolation has not been extensively explored. OBJECTIVE: To develop a protocol that allows estimation of the potential for, and avoidance of, esophageal heating. METHODS: In consecutive patients who underwent PV isolation, a thermal probe was used to monitor T° fluctuations in the esophagus during application of RF energy. The tip of the thermal probe was positioned at the level of the targeted PV and RF was discontinued for T° rise >0.5°C. The proximity of individual PVs to the esophagus was measured from the temperature probe tip to the closest posterior part of the Lasso catheter from review of biplane projections (left anterior oblique 60° and right anterior oblique 30°). These raw distances were entered into the Pythagorean theorem and the actual distance between the esophageal thermal probe and PV antrum was determined. RESULTS: The study cohort included 44 patients (60 ± 11 years, 61% male, 57% lone AF). The thermal probe in the esophagus was closer to the left-sided PVs (left common pulmonary vein: 20.9 ± 13 mm, left upper pulmonary vein: 20.5 ± 11 mm, left lower pulmonary vein: 23.4 ± 10 mm) than the right-sided ones (right common pulmonary vein: 31.0 ± 11 mm, right upper pulmonary vein: 41.9 ± 18 mm, right lower pulmonary vein: 34.5 ± 16 mm). A T° increase >0.5° C occurred during 116/1,495 (7.8%) deliveries. A T° rise was more likely during ablation of left-sided PVs than right-sided PVs (55% vs 10%, P < 0.0001) and when RF was delivered ≤ 24 mm from the esophagus (sensitivity 91%, specificity 81%, positive predictive value 75%, and negative predictive value 93%). CONCLUSION: A thermal probe placed in the esophagus provides real-time T° monitoring and anatomic localization. A T° rise is more likely during ablation of left PVs and during RF deliveries within 24 mm of the esophageal thermal probe.

Isolated cervical rib fracture.

Isolated fracture of a cervical rib is a very rare entity. Cervical rib fracture due to heavy backpack usage is a new occupational hazard for students. Cervical rib fracture usually presents as a painless swelling or as thoracic outlet syndrome. We report two patients with cervical rib fractures, one of them secondary to backpack usage, and review the available literature.

A rare case of congenital diaphragmatic hernia with ectopic liver and absent pericardium.

We present a 37-year-old woman with a rare combination of absent pericardium with congenital diaphragmatic hernia. Only 3 patients with congenital diaphragmatic hernia with complete absence of pericardium and ectopic liver have been described, and all of them were neonates. This interesting case gives us an opportunity to study the natural history of this rare combination of anatomic defect and consolidate the existing scarce data on this condition.

Prevalence, predictors, and prognosis of atrial fibrillation early after pulmonary vein isolation: findings from 3 months of continuous automatic ECG loop recordings.

INTRODUCTION: Following pulmonary vein isolation (PVI) for atrial fibrillation (AF), early recurrences are frequent, benign and classified as a part of a "blanking period." This study characterizes early recurrences and determines implications of early AF following PVI. METHODS AND RESULTS: Seventy-two consecutive patients (59.8 +/- 10.7 years, 69% male) were studied following PVI for paroxysmal or persistent AF. Subjects were fitted with an external loop recorder for automatic, continuous detection of AF recurrence for 3 months. AF prevalence was highest 2 weeks after PVI (54%) and declined to an eventual low of 22%. A significant number (488, 34%) of recurrences were asymptomatic; however, all patients with > or =1 AF event had > or =1 symptomatic event. No clear predictor of early recurrence was identified. Forty-seven (65%) patients had at least 1 AF episode, predominantly (39 of 47 patients, 83%) within 2 weeks of PVI. Of the 33 patients who did not experience AF within the first 2 weeks, 85% (28/33) were complete responders (P = 0.03) at 12 months. Recurrence at any time within 3 months was not associated with procedural success or failure. CONCLUSIONS: Early AF recurrence peaks within the first few weeks after PVI, but continues at a lower level until the completion of monitoring. A blanking period of 3 months is justified to identify patients with AF recurrences that do not portend procedure failure. Freedom from AF in the first 2 weeks following ablation significantly predicts long-term AF freedom.

The utility of 12-lead Holter monitoring in patients with permanent atrial fibrillation for the identification of nonresponders after cardiac resynchronization therapy.

OBJECTIVES: This study sought to determine the incidence of ineffective capture using 12-lead Holter monitoring and to assess whether this affects response to cardiac resynchronization therapy (CRT). BACKGROUND: Cardiac resynchronization therapy is used in patients with atrial fibrillation (AF), prolonged QRS duration, and heart failure in the setting of ventricular dysfunction. The percentage of ventricular pacing is used as an indicator of adequate biventricular (BiV) pacing. Although device counters show a high pacing percentage, there may be ineffective capture because of underlying fusion and pseudo-fusion beats. METHODS: We identified 19 patients (age 72 +/- 8 years, ejection fraction 18 +/- 5%), with permanent AF who underwent CRT. All patients received digoxin, beta-blockers, and amiodarone for rate control; device interrogation showed >90% BiV pacing. Patients had a 12-lead Holter monitor to assess the presence of effective (>90% fully paced beats/24 h) pacing. At 12 months post-CRT, the New York Heart Association functional class was reassessed and an echocardiogram was obtained and compared with pre-CRT. RESULTS: Only 9 (47%) patients had effective pacing. The other 10 (53%) patients had 16.4 +/- 4.6% fusion and 23.5 +/- 8.7% pseudo-fusion beats. Long-term responders (> or =1 New York Heart Association functional class improvement) to CRT had a significantly higher percentage of fully paced beats (86.4 +/- 17.1% vs. 66.8 +/- 19.1%; p = 0.03) than nonresponders. CONCLUSIONS: Pacing counters overestimate the degree of effective BiV pacing in patients with permanent AF undergoing CRT therapy. Only patients with complete capture responded clinically to CRT. These findings have important implications for the application of CRT to patients with permanent AF and heart failure.

Cardiac resynchronization therapy and atrial fibrillation.

Cardiac resynchronization therapy (CRT) is an important advance for the treatment of end-stage heart failure (HF). About 15-50% of HF is complicated by atrial fibrillation (AF), associated with worsened outcomes. The presence of AF may interfere with optimal delivery of CRT due to competition with biventricular (BiV) capture by conducted beats. Pacing algorithms in newer devices may not ensure consistent CRT delivery during periods of rapid ventricular rates. Atrioventricular junction ablation with permanent pacing eliminates interference by conducted beats and provides complete BiV capture and is associated with improved outcomes. Catheter ablation of AF is another promising alternative to maintain sinus rhythm in patients with AF and HF. However, the optimal indications for CRT delivery for patients in this complex cohort remain to be assessed in randomized clinical trials.

Selective implantation of cardioverter-defibrillators in patients with genetic heart disease and sudden death risk.

The implantable cardioverter-defibrillator (ICD) therapy is an established intervention for the prevention of sudden cardiac death (SCD) in patients with significant left ventricular dysfunction. Multiple randomized clinical trials have studied the use of ICD for the primary and secondary SCD. These studies were performed in patients with left ventricular dysfunction from coronary artery disease or dilated cardiomyopathy, and the marker of reduced ejection fraction has emerged for selecting patients who would benefit from ICD therapy. Currently, for most of these patients the decision to implant, or not, is determined by relatively straightforward paradigms. The same cannot be said for the genetic cardiac diseases associated with SCD--long QT syndrome, Brugada syndrome, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular dysplasia. Indications for ICD in these conditions are very much a work-in-progress.

The role of antiarrhythmic drug therapy for the prevention of sudden cardiac death.

Sudden cardiac death (SCD) accounts for more than 300,000 deaths annually in the United States alone. The utility of antiarrhythmic drugs in survivors of SCD (secondary prevention) is limited because of their incomplete efficacy and long-term toxicity. Efforts to target primary prevention of SCD have focused on left ventricular dysfunction in conjunction with congestive heart failure. Antiarrhythmic drugs are not able to decrease mortality in this patient population either; in fact, certain drugs may actually increase overall mortality. In both primary and secondary prevention patients, only implantable cardioverter-defibrillator implantation is associated with improved survival. Antiarrhythmic drugs like azimilide, dofetilide, sotalol, and amiodarone can be used as adjunct treatment for management of atrial arrhythmias and to decrease implantable cardioverter-defibrillator shocks. There is an unmet need for more effective and less toxic antiarrhythmic medications.

Suicide by combined insulin and glipizide overdose in a non-insulin dependent diabetes mellitus physician: a case report.

A case of self-injected insulin intoxication with an oral hypoglycaemic agent glipizide overdose in a type-II/non-insulin dependent diabetes mellitus (NIDDM) individual, a physician by profession, is presented with a review of the literature. The case demonstrates the need for thorough scene investigation, perusal of clinical details and complete autopsy to certify the death caused by combined insulin and glipizide overdose, and the manner of death. A meticulous search in the English literature reveals that hardly any fatal cases of combined insulin and glipizide overdose have been reported, with almost no cases from India, thus making this case report relevant and unique.