Left bundle branch pacing utilizing three dimensional mapping.

INTRODUCTION: Permanent His bundle pacing is feasible and effective in patients with atrioventricular block or left bundle branch block. However, pacing thresholds to capture the distal His bundle is often higher. Recently left bundle branch area pacing (LBBP) has been shown to be feasible by advancing the lead transvenously, deep into the interventricular septum to reach the left ventricular endocardial surface. In this article we describe the utility of three dimensional (3D) mapping to achieve LBBP. METHODS: Ensite Precision (Abbott) mapping system was used to perform LBBP. A decapolar catheter was used to create 3D map of right atrium and right ventricle (RV). Regions of interest (His bundle, potential LBBP sites of interest in RV) were tagged in the 3D map. The LBBP lead was implanted utilizing the 3D map. The lead depth in the septum was assessed in the 3D map. RESULTS: LBBP was performed in three patients: chronic LBBB and intermittent 2:1 atrioventricular block; atrioventricular (AV) node ablation and conduction system pacing; and bifascicular block and intermittent AV block in a patient with severe left ventricular hypertrophy. LBBP was successful in all three patients. The lead depth in the interventricular septum was 12, 11, and 21 mm, respectively as assessed by 3D mapping. CONCLUSIONS: Three-dimensional mapping was helpful in achieving LBBP in patients with LBBB, severe left ventricular hypertrophy or during AV node ablation. 3D mapping also facilitated easy assessment of lead depth during and after lead fixation. 3D mapping techniques may be a valuable tool to reduce the learning curve of implanters with minimal experience in LBBP.

An Uncommon Complication With Use of Topical Local Anesthetic Agents: Methemoglobinemia.

Although the use of topical local anesthetics is generally safe, several potentially fatal complications have been reported. Methemoglobinemia is a rare but potentially fatal complication. Methemoglobin is a naturally occurring oxidized metabolite of hemoglobin, and physiologic levels (<1%) are normal. Methemoglobinemia can be congenital or acquired. Several drugs including topical anesthetic agents like benzocaine can induce this condition. Sudden appearance of cyanosis, with a disproportionately better oxygen saturation of 85% after use of local anesthetics can be a helpful for diagnosis.

I lost weight, but I became weak and cannot walk--a case of nutraceutical (T3)-induced thyrotoxic periodic paralysis.

Thyrotoxic periodic paralysis (TPP) is a rare reversible cause of paralysis and cramping. TPP is usually precipitated by common causes of thyrotoxicosis such as Grave disease or multinodular goiter. TPP precipitated by exogenous triiodothyronine (T3) intake is an extremely rare occurrence with only 3 cases reported to date. We now report a 24-year-old healthy manual laborer who developed quadriparesis during a period of rest after heavy exertion and carbohydrate intake. He had severe hypokalemia (potassium level 1.9 mmole/L). Correction of his hypokalemia reversed the paralysis without rebound hyperkalemia. After a detailed history review, he reported that he had been consuming nutraceuticals containing T3 for 1 month to lose weight, and laboratory studies confirmed factitious T3 toxicosis. There was no evidence of renal or gastrointestinal potassium wasting. This episode of TPP was the first manifestation of thyrotoxicosis in this patient, and avoidance of T3 intake prevented more episodes.

Chest pain and diarrhea: a case of Campylobacter jejuni-associated myocarditis.

BACKGROUND: Diarrhea and chest pain are common symptoms in patients presenting to the emergency department (ED). However, rarely is a relationship between these two symptoms established in a single patient. OBJECTIVE: Describe a case of Campylobacter-associated myocarditis. CASE REPORT: A 43-year-old man with a history of hypertension presented to the ED with angina-like chest pain and a 3-day history of diarrhea. Electrocardiogram revealed ST-segment elevation in the lateral leads. Coronary angiogram revealed no obstructive coronary artery disease. Troponin T rose to 1.75 ng/mL. Cardiac magnetic resonance imaging showed subepicardial and mid-myocardial enhancement, particularly in the anterolateral wall and interventricular septum, consistent with a diagnosis of myocarditis. Stool studies were positive for Campylobacter jejuni. CONCLUSIONS: Campylobacter-associated myocarditis is rare, but performing the appropriate initial diagnostic testing, including stool cultures, is critical to making the diagnosis. Identifying the etiology of myocarditis as bacterial will ensure that appropriate treatment with antibiotics occurs in addition to any cardiology medications needed for supportive care.

Electrocardiographic predictors of sudden cardiac death in patients with left ventricular hypertrophy.

BACKGROUND: Left ventricular hypertrophy (LVH) has been associated with increased risk of sudden cardiac death (SCD), and improvements in risk stratification methodology are warranted. METHODS: We evaluated electrocardiographic intervals as potential markers of SCD risk in LVH. Corrected QT, QRS, and JT intervals were evaluated in consecutive cases with SCD and LVH from the ongoing Oregon Sudden Unexpected Death study who underwent a 12-lead electrocardiogram (EKG) and echocardiogram prior to and unrelated to the SCD event. Comparisons of age, gender, body mass index, LV ejection fraction, and EKG intervals together with clinical conditions (hypertension and diabetes) were conducted with geographically matched controls that had coronary artery disease but no history of ventricular arrhythmias or cardiac arrest. LVH was determined using the modified American Society of Echocardiography equation for LV mass. Independent samples t-test, Pearson's chi-square test, and multiple logistic regression were used for statistical comparisons. RESULTS: Of the 109 cases and 49 controls who met study criteria, age, gender, and comorbidities were similar among cases and controls. The mean LV mass index was not significantly different in cases compared to controls. However mean QTc (470.6 ± 53.6 ms vs 440.7 ± 38.7 ms; P < 0.0001) and QRS duration (113.6 ± 30.0 ms vs 104.9 ± 18.7 ms; P = 0.03) were significantly higher in cases than controls. In logistic regression analysis, prolonged QTc was the only EKG interval significantly associated with SCD (OR 1.72 [1.23-2.40]). CONCLUSION: Prolonged QTc was independently associated with SCD among subjects with LVH and merits further evaluation as a predictor of SCD in LVH.

Prospective evaluation of feasibility and electrophysiologic and echocardiographic characteristics of left bundle branch area pacing.

BACKGROUND: His bundle pacing (HBP) is the most physiologic form of pacing but associated with higher thresholds and lower success in patients with His-Purkinje conduction disease. Recent reports have described transvenous left bundle branch area pacing (LBBAP). OBJECTIVE: We aimed to prospectively evaluate the feasibility and the electrophysiologic and echocardiographic characteristics of LBBAP. METHODS: Patients requiring pacing for bradycardia or heart failure indications (failed left ventricular [LV] lead) were prospectively enrolled. LBBAP was performed with a Medtronic 3830 lead. Presence of left bundle branch (LBB) potential, paced QRS morphology/duration, and peak LV activation time (pLVAT) were recorded at implant. Pacing threshold and sensing was assessed at implant and follow-up. Echocardiography was performed to assess the approximate lead location and impact on tricuspid valve function. RESULTS: LBBAP was successful in 93 of 100 (93%) patients. Mean age was 75 ± 13 years; men 69%, left bundle branch block 24%, right bundle branch block 25%, intraventricular conduction defect 8%. Indications for pacing were atrioventricular (AV) block 54%, sinus node dysfunction 23%, AV node ablation 7%, cardiac resynchronization therapy 11%, HBP lead failure 7%. Baseline QRS duration was 133 ± 35 ms. Paced QRS duration was 136 ± 17 ms. LBB potentials were observed in 63 patients with left bundle branch - ventricle (LBB-V) interval of 27 ± 6 ms. pLVAT was 75 ± 16 ms. Pacing threshold at implant was 0.6 ± 0.4 V @ 0.5 ms and R waves were 10 ± 6 mV and remained stable at median follow-up of 3 months. The lead depth in the septum was approximately 1.4 ± 0.23 cm. CONCLUSIONS: LBBAP was feasible in a high percentage of patients with low thresholds during acute follow-up. HBP and LBBAP may significantly increase the overall success of physiologic pacing.

Clinical Outcomes of Selective Versus Nonselective His Bundle Pacing.

OBJECTIVES: The aim of the study was to evaluate the clinical outcomes of nonselective (NS) His bundle pacing (HBP) compared with selective (S) HBP. BACKGROUND: HBP is the most physiologic form of ventricular pacing. NS-HBP results in right ventricular septal pre-excitation due to fusion with myocardial capture in addition to His bundle capture resulting in widened QRS duration compared with S-HBP wherein there is exclusive His bundle capture and conduction. METHODS: The Geisinger and Rush University HBP registries comprise 640 patients who underwent successful HBP. Our study population included 350 consecutive patients treated with HBP for bradyarrhythmic indications who demonstrated ≥20% ventricular pacing burden 3 months post-implantation. Patients were categorized into S-HBP or NS-HBP based on QRS morphology (NS-HBP n = 232; S-HBP n = 118) at the programmed output at the 3-month follow-up. The primary analysis outcome was a combined endpoint of all-cause mortality or heart failure hospitalization. RESULTS: The NS-HBP group had a higher number of men (64% vs. 50%; p = 0.01), higher incidence of infranodal atrioventricular block (40% vs. 9%; p < 0.01), ischemic cardiomyopathy (24% vs. 14%; p = 0.03), and permanent atrial fibrillation (18% vs. 8%; p = 0.01). The primary endpoint occurred in 81 of 232 patients (35%) in the NS-HBP group compared with 23 of 118 patients (19%) in the S-HBP group (hazard ratio: 1.38; 95% confidence interval: 0.87 to 2.20; p = 0.17). Subgroup analyses of patients at greatest risk (higher pacing burden or lower left ventricular ejection fraction) revealed no incremental risk with NS-HBP. CONCLUSIONS: NS-HBP was associated with similar outcomes of death or heart failure hospitalization when compared with S-HBP. Multicenter risk-matched clinical studies are needed to confirm these findings.

Amphetamine-related ischemic colitis causing gastrointestinal bleeding.

A 43-year-old woman presented with acute lower intestinal bleeding requiring blood transfusion. Multiple initial investigations did not reveal the cause of the bleeding. Colonoscopy performed 2 days later showed features suggestive of ischemic colitis. On detailed history, the patient admitted to using amphetamines, and her urine drug screen was positive for them. She was managed conservatively and advised not to use amphetamines again. She did not have any recurrence on 2-year follow-up.

Streptococcus agalactiae pyomyositis in diabetes mellitus.

Pyomyositis is an acute infectious disorder affecting the skeletal muscle. Although seen more commonly in the tropics, cases are being reported in temperate countries, including the United States. We report a case of nontropical pyomyositis in a 58-year-old diabetic man who presented with a vague chest wall swelling. His initial clinical presentation and imaging findings suggested an intramuscular hematoma. He later developed fever with increased swelling, and pyomyositis was diagnosed after an aspiration of the swelling yielded Streptococcus agalactiae. Aspiration of the abscess and the use of appropriate antibiotics led to complete resolution of the disease. We discuss possible factors in diabetics that might predispose them to pyomyositis.

Idiopathic intracranial hypertension: ongoing clinical challenges and future prospects.

Idiopathic intracranial hypertension (IIH) is an uncommon disorder characterized by increased intracranial pressure without radiological or laboratory evidence of intracranial pathology except empty sella turcica, optic nerve sheath with filled out cerebrospinal fluid spaces, and smooth-walled nonflow-related venous sinus stenosis or collapse. This condition typically affects obese women. The incidence of IIH is increasing with the rising prevalence of obesity. Persistent headache is the most common symptom. Visual impairment is a serious complication that may not be recognized by the patients. This paper reviews clinical manifestations, diagnostic challenges, and current treatments of IIH in adults. Various imaging modalities have been studied on their validity for detection of IIH and papilledema. This review also includes new studies on medical, surgical, and interventional management of this condition. Acetazolamide and topiramate are the only two medications that have been studied in randomized controlled trials about their efficacy in treatment of IIH. In patients who have severe visual impairment or progressive visual deterioration despite medical management, surgical or interventional treatment may be considered. The efficacy and complications of cerebrospinal fluid diversion, optic nerve sheath fenestration, and endovascular venous stenting reported in the last 3 decades have been summarized in this review. Finally, the prospective aspects of biomarkers and treatments are proposed for future research.

An Uncommon Association of Familial Partial Lipodystrophy, Dilated Cardiomyopathy, and Conduction System Disease.

A 46-year-old African American woman presented with severe respiratory distress requiring intubation and was diagnosed with nonischemic cardiomyopathy. She had the typical phenotype of familial partial lipodystrophy 2 (FPLD2). Sequence analysis of LMNA gene showed a heterozygous missense mutation at exon 8 (c.1444C>T) causing amino acid change, p.R482W. She later developed severe coronary artery disease requiring multiple percutaneous coronary interventions and coronary artery bypass surgery. She was later diagnosed with diabetes, primary hyperparathyroidism, and euthyroid multinodular goiter. She had sinus nodal and atrioventricular nodal disease and had an implantable cardioverter defibrillator implantation due to persistent left ventricular dysfunction. The device eroded through the skin few months after implantation and needed a re-implant on the contralateral side. She had atrial flutter requiring ablation. This patient with FPLD2 had most of the reported cardiac complications of FPLD2. This case is presented to improve the awareness of the presentation of this disease among cardiologists and internists.

Indications and appropriateness of inferior vena cava filter placement.

BACKGROUND: Several professional societies have published guidelines for the placement of inferior vena cava (IVC) filters. The authors wanted to determine how frequently patients in their hospital had IVC filters placed based on current indications and to compare guidelines published by the American College of Chest Physicians (ACCP) and the Society of Interventional Radiologists (SIR). METHODS: The authors performed a structured review of the medical records of 180 patients identified by International Classification of Diseases, Ninth Revision, codes who had IVC filter placement at their hospital between July 1, 2007, and June 30, 2012. Indications for placement were based on current recommendations from the ACCP and SIR. RESULTS: These patients had a mean age of 62.4 ± 15.7 years and included 96 men and 84 women. One hundred forty patients had a history of deep venous thrombosis, pulmonary emboli or both. One hundred seven patients had permanent filters inserted, 34 had retrievable filters inserted and 39 had an unknown type of filter inserted. Forty-one patients (22.7%) had no definite indication for IVC filter insertion based on SIR guidelines, and 72 (40%) had no definite indication based on ACCP guidelines. There was a good agreement between the ACCP guidelines and the SIR guidelines when indications were categorized. Only one retrievable filter was removed. CONCLUSIONS: Twenty to forty percent of the patients with IVC filter insertions in their hospital had no definite indication documented in the medical record. A performance improvement activity to evaluate the use of IVC filters, such as a dedicated clinic, may be useful.

Mach band sign: an optical illusion.

The chest radiograph of a 63-year-old woman who was found unresponsive was concerning for pneumopericardium, but lacked the other corroborative features suggestive of pneumopericardium. None of the follow-up chest radiographs showed evidence of air around the heart. The radiolucent shadow that mimicked pneumopericardium in this case was due to an artifact known as Mach band sign, an illusion created by lateral inhibition in the light receptors in the retina.

Syndrome of inappropriate antidiuretic hormone secretion associated with prolonged keterolac use.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used analgesics. Although rare, clinicians need to keep in mind that their use may precipitate hyponatremia and syndrome of inappropriate antidiuretic hormone (SIADH), especially in high-risk patients with multiple comorbidities. In the kidneys, prostaglandins attenuate the water retention effect of antidiuretic hormone. NSAIDs cause a decrease in prostaglandins in the kidney and therefore the effect of ADH is potentiated. We report a case of SIADH that was associated with keterolac in a 65-year-old male. SIADH has not previously been reported with keterolac, a strong NSAID with comparable analgesic effect as morphine and meperidine. Keterolac may have unique properties different from other NSAIDS which may predispose to the development of hyponatremia. In our case, prolonged use of keterolac may have contributed to the development of SIADH and caution is needed when keterolac is used for prolonged duration. A review of the literature regarding development of SIADH and hyponatremia in the setting of NSAIDs is also presented.

The alien hand syndrome.

A 77-year-old woman presented with the complaint of observing her left hand moving without her knowledge while watching television. Her left hand stroked her face and hair as if somebody was controlling it. These movements lasted only half an hour but on recovery, she had left hemiparesis. Alien hand syndrome as the presentation of cardioembolic stroke is extremely rare but can be terrifying to patients.

Fatal Clostridium septicum infection in a patient with a hematological malignancy.

A 49-year-old woman with acute myeloid transformation of myelodysplastic syndrome was admitted with mild erythema and pain in the right thigh and left forearm. She was doing well and had been discharged the previous day after consolidation chemotherapy. Examination showed only mild erythema and tenderness of the right thigh. She was started on broad-spectrum antibiotics. Discoloration progressed rapidly, and within hours the right femoral and left brachial pulses were not palpable. She was taken to the operating room for a suspicion of embolic arterial occlusion. Surgical incision, however, revealed extensive necrosis of the tissues with the presence of gas. Her relatives did not want her to undergo amputation. The patient developed refractory hypotension and died within 15 hours of presentation. Blood samples later tested positive for Clostridium septicum. This case is presented to create awareness about the subtle presentation and rapid progression of this infection, which can lead to death in less than 24 hours.

The association of α-blockers and 5-α reductase inhibitors in benign prostatic hyperplasia with fractures.

BACKGROUND: Alpha-blockers and 5-alpha reductase inhibitors are common drugs used to treat benign prostatic hyperplasia (BPH), a prevalent problem in older men associated with significant morbidity and cost. Data regarding how these medications affect skeletal health and fracture risk remain scarce. METHODS: Studies were identified by searching PubMed, EMBASE, the Cochrane library and Thomson Reuters Web of Knowledge. Studies involving BPH patients that reported odds ratio (OR) estimates with 95% confidence intervals (CIs) for the association between fractures and exposure to 5-alpha reductase inhibitors or alpha-blockers were included. Pooled ORs were calculated using the random-effects model. RESULTS: Three studies addressed fracture risk in patients exposed to 5-alpha reductase inhibitors (21,366 fracture cases). Four studies addressed fracture risk in patients exposed to alpha-blockers (22,051 fracture cases). The pooled OR for fractures with 5-alpha reductase inhibitor use was 0.9 (95% CI = 0.7-1.1). For hip/femur fractures with 5-alpha reductase inhibitor use, the pooled OR was 0.8 (95% CI = 0.7-1.0). The pooled OR for fractures with alpha-blockers was 1.1 (95% CI = 0.9-1.3). There was significant statistical heterogeneity among studies for alpha-blockers. CONCLUSIONS: In patients with BPH, exposure to 5-alpha reductase inhibitors was not associated with change in fracture risk. The 5-alpha reductase inhibitors may have a small protective effect against hip/femur fractures although this was not statistically significant. Although alpha-blockers were not associated with change in fracture risk, caution is required when interpreting the results as significant heterogeneity was present.

Intracranial hypertension and intracranial hypotension causing headache in the same patient.

Intracranial hypertension and intracranial hypotension are on the opposite end of the intracranial pressure spectra. It is extremely uncommon for both to cause headache in the same patient within a span of several days. This report describes a young man with intracranial hypertension who developed a severe excruciating headache due to intracranial hypotension after a diagnostic lumbar puncture. It is paradoxical that lumbar puncture, which is supposed to be a treatment option for patients with idiopathic intracranial hypertension, leads to headache due to intracranial hypotension.

Cardiac repolarization abnormalities among patients with various stages of chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease (CKD) are at increased risk of life-threatening cardiovascular arrhythmias. Although these arrhythmias are usually secondary to structural heart diseases that are commonly associated with CKD, a significant proportion of cases with sudden cardiac death have no obvious structural heart disease. This study aims to explore the relationship of cardiac repolarization in patients with CKD and worsening kidney function. HYPOTHESIS: There is cardiac repolarization abnormalities among patients with chronic kidney disease. METHODS: This was a retrospective, chart-review study of admissions or clinic visits to a university hospital between 2005 and 2010 by patients with a diagnosis of CKD. Inclusion criteria selected patients who had 12-lead surface electrocardiography (ECG), renal function tests within 24 hours, and transthoracic echocardiography within 6 months. Cases with a documented etiology for the corrected Qt (Qtc) interval prolongation including structural heart disease, QT prolonging drugs, or relevant disease conditions, were excluded. RESULTS: Our sample size was 154 ECGs. Two-thirds of patients with CKD had QTc interval prolongation, and about 20% had a QTc interval >500 ms. QTc interval was significantly different and increased with each successive stage of CKD using the Bazett (P < 0.006) or Fridericia (P = 0.03) formula. QTc interval correlated significantly with serum creatinine (P = 0.01). These finding were independent of age, gender, potassium, and calcium concentrations. CONCLUSIONS: The progression of CKD resulted in a significant delay of cardiac repolarization, independent of other risk factors. This effect may potentially increase the risk of sudden cardiac death, and may also increase the susceptibility of drug-induced arrhythmia.