Comparison of anterior mitral line and mitral isthmus line for ablation of mitral annular flutter.

BACKGROUND: Mitral annular flutter (MAF) is the most common left atrial macro-reentrant arrhythmia following catheter ablation of atrial fibrillation (AF). The best ablation approach for this arrhythmia remains unclear. METHODS: This single-center, retrospective study sought to compare the acute and long-term outcomes of patients with MAF treated with an anterior mitral line (AML) versus a mitral isthmus line (MIL). Acute ablation success, complication rates, and long-term arrhythmia recurrence were compared between the two groups. RESULTS: Between 2015 and 2021, a total of 81 patients underwent ablation of MAF (58 with an AML and 23 with a MIL). Acute procedural success defined as bidirectional block was achieved in 88% of the AML and 91% of the MIL patients respectively (p = 1.0). One year freedom from atrial arrhythmias was 49.5% versus 77.5% and at 4 years was 24% versus 59.6% for AML versus MIL, respectively (hazard ratio [HR]: 0.38, confidence interval [CI]: 0.17-0.82, p = .009). Fewer patients in the MIL group had recurrent atrial flutter when compared to the AML group (HR: 0.32, CI: 0.12-0.83, p = .009). The incidence of recurrent AF, on the other side, was not different between both groups (21.7% vs. 18.9%; p = .76). There were no serious adverse events in either group. CONCLUSION: In this retrospective study of patients with MAF, a MIL compared to AML was associated with a long-term reduction in recurrent atrial arrhythmias driven by a reduction in macroreentrant atrial flutters.

New pattern of atypical advanced interatrial block.

INTRODUCTION: Interatrial block (IAB) is defined as prolonged P-wave duration (≥ 120 ms) due to delayed conduction in the Bachmann bundle. This is readily identifiable using surface electrocardiogram (ECG). Advanced IAB can be classified as typical and atypical. Atypical IAB can be further categorized by (i) duration or (ii) morphology. In this report, we have identified a new pattern of atypical IAB with triphasic morphology of the P-wave in the inferior leads. METHODS: Two clinical cases were evaluated including surface ECGs. P-wave durations and amplitudes were measured with digital calipers using ECG analysis software (MUSE, GE HealthCare). Comparisons were made using prior data to evaluate IAB and P-wave duration and morphology. RESULTS: A new pattern of atypical advanced IAB shows prolonged P-wave duration (P wave >160 ms) and triphasic morphology in all inferior leads with P +/+/- and P +/-/+, respectively. We speculate that triphasic P-waves in the inferior leads represent three moments of atrial depolarization; from right to left. CONCLUSION: This study describes a novel pattern of atypical advanced IAB. Further investigation regarding the increased risk of atrial fibrillation and stroke associated with this new pattern is warranted in the future.

Positional syncope occurring just at the right time in a patient with a permanent pacemaker: A case report.

We present an unusual case of positional syncope occurring years after pacemaker implantation. Syncope was caused by a pacemaker lead fracture, which resulted from subclavian crush syndrome. The syncope occurred incidentally during hospital admission and was timely diagnosed using an integrated approach of history taking, examination findings, device interrogation and radiographic parameters. The patient subsequently underwent lead and device alteration which led to resolution of her symptoms.

Two Cases of Cardiac Implantable Electronic Device Placement via Persistent Left Superior Vena Cava.

Persistent left superior vena cava (PLSVC) is the most common variation of anomalous venous return to the heart and present in 0.1-0.5% of the general population. The left anterior cardinal veins typically obliterate during early cardiac development but failure of involution results in PLSVC. It is an asymptomatic congenital anomaly, usually discovered while performing interventions through the left subclavian vein or during cardiovascular imaging. PLSVC can be associated with cardiac arrhythmias and congenital heart disease. We present two cases of PLSVC: first, a 68-year-old male who presented with complete heart block, for which a temporary pacemaker was initially inserted followed by a permanent pacemaker; second, a 53-year-old female with a history of hypertension and ischemic cardiomyopathy with a left ventricular ejection fraction of 25%, and a survivor of sudden cardiac death, who underwent an implantable cardioverter-defibrillator (ICD) for secondary prevention. Both cases of PLSVC were detected incidentally during the transvenous approach to the heart. PLSVC was suspected by the unusually left medial position of the lead, while cineflouroscopy showed the venous trajectory toward the coronary sinus and drainage into the right atrium. It is technically difficult to cross the wire through the tricuspid valve when coming from the PLSVC and coronary sinus without making a loop in the right atrium, which is known as a wide loop technique. PLSVC is an uncommon anomalous anatomical variant and should be recognized appropriately by specialists who frequently carry out procedures through the left subclavian vein, such as implantation of permanent pacemaker, ICD and cardiac resynchronization therapy. It should also be recognized that wide loop formation of the right ventricular lead in the right atrium is helpful to cross the tricuspid valve and to affix the lead in the right ventricle. LEARNING POINTS: Persistent left superior vena cava is an anatomical variant that should be recognized by specialists who frequently carry procedures through the left subclavian vein (e.g. implantation of a permanent pacemaker, implantable cardioverter-defibrillator and cardiac resynchronization therapy).Maneuvers like wide loop formation of the right ventricular lead in the right atrium is helpful to cross the tricuspid valve and to affix the lead in the right ventricle.The cardiac imaging specialist should also suspect and rule out PLSVC on encountering a dilated coronary sinus on any imaging modality.

Perception of Diabetic Patients Regarding Basal Bolus Insulin Injections and Outcome of its Use.

OBJECTIVE: To assess the perceptions regarding basal bolus insulin injections and the changes in blood glucose levels and glycosylated hemoglobin (HbA1c) before and after 3 months of such treatment in diabetic patients. STUDY DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: Department of Endocrinology, Liaquat National Hospital, Karachi, from December 2014 to March 2015. METHODOLOGY: A total of 222 diabetic patients started on basal bolus insulin injection were enrolled and asked to answer 17 questions. Those with complications of diabetes were excluded. Fasting blood glucose (FBS), random blood glucose (RBS) and HbA1c levels were checked initially, and after 3 months of getting basal bolus insulin. Paired t-test and chi-square test were used for determining p-value with significance at p < 0.05. RESULTS: Majority (n=217, 97.7%) of the patients were previously taking other insulins. Before starting this treatment, the mean FBS was 260.5 ±52.2 mg/dl, RBS was 385.5 ±47.61 mg/dl and HbA1c was 12.76 ±1.92%. After 3 months of treatment, FBS improved to 117.9 ±14.2 mg/dl, RBS was 156.7 ±17.09 mg/dl and HbA1c was 7.72 ±4.41% (p < 0.001). Two hundred and sixteen (97.3%) patients believed that basal bolus insulin was started as their diabetes worsened; 157 (70.70%) thought that their blood glucose control would improve with the use of this form of insulin. One hundred and ninety four (87.4%) had fear of needle injections. Perceptions regarding hypoglycemia with this form of insulin were observed in 157 (70.7%). One hundred and twenty seven (84.1%) of the females and 51 (71.8%) of the males thought that the basal bolus insulin regimen was too expensive (p=0.032). CONCLUSION: There were many misconceptions in patients who were started on basal bolus insulin. Marked improvement in blood glucose levels and HbA1c were observed after the use of this regimen.

Nephro-protective effect of vitamin C and Nigella sativa oil on gentamicin associated nephrotoxicity in rabbits.

Oxidative stress causes the generation of reactive oxygen species (ROS) that lead to nephrotoxicity. An aminoglycoside, gentamicin, has pronounced nephrotoxic effect in humans and animals and this study was planned to observe the nephro-protective effect of antioxidants, vitamin C and Nigella sativa oil. Serum creatinine, blood urea nitrogen, and antioxidant activity were measured as indicators of nephrotoxicity for all the groups of rabbits. Results showed that vitamin C and Nigella sativa oil both had nephro-protective effect as they lowered the values of nephrotoxicity indicators (serum creatinine, blood urea nitrogen, and antioxidant activity) as compared to gentamicin control group values. When these two antioxidants were given as combination, they proved to have synergistic nephro-protective effect.

Rapid spread of carbapenem-resistant Klebsiella pneumoniae in New York City: a new threat to our antibiotic armamentarium.

BACKGROUND: Carbapenem antibiotics are used to treat serious infections caused by extended-spectrum beta-lactamase-carrying pathogens. Carbapenem resistance has been unusual in isolates of Klebsiella pneumoniae. In this study, the prevalence and molecular epidemiologic characteristics of carbapenem-resistant K pneumoniae are analyzed, and the experience involving 2 hospital outbreaks is described. METHODS: A citywide surveillance study was conducted in hospitals in Brooklyn. An observational study involving subsequent outbreaks at 2 hospitals was undertaken. Isolates were genetically fingerprinted by ribotyping and were examined for the presence of KPC-type carbapenem-hydrolyzing beta-lactamases. RESULTS: Of 602 isolates of K pneumoniae collected during the citywide surveillance study, 45% had extended-spectrum beta-lactamases. Of the extended-spectrum beta-lactamase-producing isolates, 3.3% carried the carbapenem-hydrolyzing beta-lactamase KPC-2. Several isolates were reported by the clinical microbiology laboratories as being susceptible to imipenem. Although all the isolates were resistant using agar diffusion methods, minimal inhibitory concentrations of imipenem were substantially lower for several isolates using standard broth microdilution tests and were highly dependent on the inoculum used. Two hospitals experienced the rapid spread of carbapenem-resistant isolates involving 58 patients. Overall 14-day mortality for bacteremic patients was 47%. Most isolates belonged to a single ribotype. CONCLUSIONS: Carbapenem-resistant K pneumoniae isolates are rapidly emerging in New York City. The spread of a strain that possesses a carbapenem-hydrolyzing beta-lactamase has occurred in regional hospitals. Because these isolates are resistant to virtually all commonly used antibiotics, control of their spread is crucial. However, automated systems used for susceptibility testing may not accurately identify all these isolates, which will severely hamper control efforts.

Citywide emergence of Pseudomonas aeruginosa strains with reduced susceptibility to polymyxin B.

OBJECTIVES: To determine the prevalence of Pseudomonas aeruginosa isolates with reduced susceptibility to polymyxin B, and to assess the in vitro activity of antibiotic combinations. METHODS: All unique patient isolates of P. aeruginosa were collected from 11 Brooklyn, NY hospitals during a three month period in 2003. Isolates with reduced susceptibility to polymyxin B (MIC > 2 mg/L) underwent ribotyping. The activity of polymyxin B combined with rifampicin, azithromycin and/or imipenem was tested by the chequerboard and time-kill methods against a subset of isolates. RESULTS: Of 527 isolates, only 61% were susceptible to imipenem. Twenty-five isolates (5%), from 8/11 hospitals, had reduced susceptibility to polymyxin B (MICs 4-8 mg/L), compared with 0/691 isolates collected in 2001. Ten of 25 were resistant to multiple other antibiotic classes. Ribotyping of the isolates revealed 19 unique types. Chequerboard testing of the 10 multiresistant isolates demonstrated synergy for the combinations of polymyxin B with azithromycin, imipenem and rifampicin in 6, 2, and 1 isolates, respectively. Time-kill studies revealed bactericidal activity for the following antibiotics when combined with polymyxin B: imipenem plus rifampicin against all 10 isolates, rifampicin in 9/10 isolates, imipenem in 8/10 isolates and azithromycin in 4/10 isolates. MICs of bacteria surviving incubation in polymyxin B alone rose for 4/9 isolates (MIC range 12-48 mg/L). CONCLUSIONS: P. aeruginosa with reduced susceptibility to polymyxin B have emerged in multiple strains in Brooklyn, NY. Combinations of polymyxin B with rifampicin and/or imipenem are bactericidal. The clinical utility of these combinations remains to be determined.

Detection of KPC carbapenem-hydrolyzing enzymes in Enterobacter spp. from Brooklyn, New York.

Enterobacter spp. are rarely resistant to carbapenems. In this report, one Enterobacter sp. isolate possessed bla(KPC-3) and two possessed bla(KPC-2). For all three strains, the imipenem MICs were dependent on the inoculum and testing method; two were reported by the clinical laboratories to be carbapenem susceptible. Improved detection methods will be necessary to identify these enzymes.

Gram-negative Diplococcal Respiratory Infections.

Human respiratory tract infections caused by gram- negative diplococci continue to remain significant issues in health care. Although not addressed as frequently as the classical diplococcal pneumonia, the gram-positive Streptococcus pneumoniae (the pneumococcus), infections due to Neisseria meningitidis (the meningococcus), and Moraxella catarrhalis (formerly called both Neisseria catarrhalis and Branhamella catarrhalis) are addressed here including their microbiology, respiratory tract manifestations, antimicrobial treatment, and potential prevention with immunization.