A Study of Unusual Pacemaker Infection by Mycobacterium Tuberculosis in Indian Patients

Background

The expanding clinical indications of cardiac rhythm management have led to an increased use of pacemaker implantation which is associated with increased incidence of pacemaker infections. Staphylococcus aureus and epidermidis account for the vast majority of pacemaker infections. Pacemaker infection due to Mycobacterium tuberculosis (M. tuberculosis) is very rare, only few cases having been reported till date.

Methods

We describe here a study of three patients of pacemaker pocket infection with M. tuberculosis.

Conclusion

The possibility of mycobacterial pacemaker infection should always be kept in mind in patients with delayed pacemaker infection.     

The Effects Of Short Time Right Ventricular Pacing On Left Atrial Mechanical Functions

Objectives

Left atrium (LA) plays an important role in left ventricular filling. It is well known that right ventricular apical pacing has unfavorable effects on ventricular systolic and diastolic performance. The aim of this study is to evaluate the LA mechanical functions with 2D echocardiography in patients with a permanent pacemaker after short time ventricular pacing.

Design

Echocardiographic examination was performed in 38 patients (mean age 63.0± 10.9, 18 female) with dual chamber pacemakers or defibrillators (< 20% ventricular pacing within previous 6 months, all of them on sinus rhythm) before and after 4 hours > 90% ventricular pacing at 70 beats per minute in DDD mode with an optimal AV interval. Left atrial volumes (LAV) including at the time of mitral valve opening (Vmax), at closure (Vmin), and at the onset of atrial systole (Volp) were measured. The passive emptying, conduit, active emptying and total emptying volume, stroke volumes were also calculated.

Results

No significant differences were noted at baseline and after pacing for absolute Vmax, Volp, passive emptying, conduit, active emptying, total emptying volumes as well as the volumes indexed to body surface area (p >0.05).

Conclusions

Short - time RV pacing seems to have no acute effects on left atrial mechanical functions.     

Can Right Ventricular Pacing be Useful in the Assessment of Cavo-tricuspid Isthumus Block?

Background

Cavo-tricuspid isthmus (CTI) block is currently assessed by coronary sinus (CS) pacing or low lateral and septal atrial pacing. Occasionally, CS catheterization through the femoral route can be difficult to perform or right atrial pacing can be problematic because of catheter instability or saturation of the atrial electrograms recorded near the catheter.

Objectives

Our aim was to evaluate the feasibility of assessing cavo-tricuspid isthmus block by means of right ventricular (RV) pacing in patients with ventriculo-atrial conduction, comparing it with CS pacing.

Methods

Circumannular activation was analyzed during CS and RV pacing in consecutive patients in sinus rhythm undergoing CTI ablation for typical atrial flutter. Patients without ventriculo-atrial conduction were excluded from the study. The linear lesion was created during RV pacing and split atrial signals on the ablation line were analyzed. CTI block was confirmed by analyzing local electrograms on the line of block and circumannular activation during CS and RV pacing.

Results

Out of 31 patients, 20 displayed ventriculo-atrial conduction (64%) and were included in the study. Before ablation, during RV stimulation, the collision front of circumannular activation shifted counterclockwise in contrast with the pattern observed during CS pacing. After ablation, circumannular activation was similar during CS and RV pacing, showing fully descending lateral right atrium activation, even if double potentials registered on the ablation line were less widely split during RV pacing than CS pacing (111±26 ms vs 128±30 , p=0.0001).

Conclusions

In patients with ventriculo-atrial conduction, tricuspid annulus activation during CS and RV pacing is similar, before and after CTI ablation. The occurrence of split atrial electrograms separated by an isoelectric interval registered on the line of block can be detected during CS or RV pacing. In patients with difficult CS catheterization via the femoral vein, before trying the subclavian or internal jugular route, if retrograde ventriculo-atrial conduction is present, RV pacing can be an easy trick to assess isthmus block.     

Utilization of Electrocardiographic P-wave Duration for AV Interval Optimization in Dual-Chamber Pacemakers

Background

Empiric programming of the atrio-ventricular (AV) delay is commonly performed during pacemaker implantation. Transmitral flow assessment by Doppler echocardiography can be used to find the optimal AV delay by Ritter''s method, but this cannot easily be performed during pacemaker implantation. We sought to determine a non-invasive surrogate for this assessment. Since electrocardiographic P-wave duration estimates atrial activation time, we hypothesized this measurement may provide a more appropriate basis for programming AV intervals.

Methods

A total of 19 patients were examined at the time of dual chamber pacemaker implantation, 13 (68%) being male with a mean age of 77. Each patient had the optimal AV interval determined by Ritter''s method. The P-wave duration was measured independently on electrocardiograms using MUSE® Cardiology Information System (version 7.1.1). The relationship between P-wave duration and the optimal AV interval was analyzed.

Results

The P-wave duration and optimal AV delay were related by a correlation coefficient of 0.815 and a correction factor of 1.26. The mean BMI was 27. The presence of hypertension, atrial fibrillation, and valvular heart disease was 13 (68%), 3 (16%), and 2 (11%) respectively. Mean echocardiographic parameters included an ejection fraction of 58%, left atrial index of 32 ml/m², and diastolic dysfunction grade 1 (out of 4).

Conclusions

In patients with dual chamber pacemakers in AV sequentially paced mode and normal EF, electrocardiographic P-wave duration correlates to the optimal AV delay by Ritter''s method by a factor of 1.26.     

Intracardiac atrial signal amplitude in congenital and acquired complete heart block

Background

Good and reliable atrial sensing is a fundamental part of atrioventricular (AV) synchrony in dual chamber pacemakers. Due to the floating nature of atrial sensing electrode in single pass dual chamber pacemakers (VDD) compared with two-lead dual chamber pacemakers (DDD), they are more prone to atrial under-sensing and the resulting loss of AV synchrony. We hypothesized that there is a relation between the chronicity of AV block and the amplitude of intracardiac atrial signal amplitudes (IASA).

Methods

Detailed demographic, electrocardiographic and echocardiographic data were recorded in 34 consecutive patients with congenital and acquired complete heart block (CHB). The intracardiac atrial signal amplitudes (IASA) were recorded at implantation time, 48 hours and 2 months post-implantation and compared between the two groups of patients.

Results

The mean age of the study group was 38.73±12.53 years (congenital: 30.08±11.07, acquired: 47.38±6.5). There were no important differences in left atrial or ventricular sizes and in P-wave amplitude in lead II, but the IASA was significantly higher in the congenital group at implantation time (5.21±1.86 vs. 3.38±0.84 mV, P<0.001) and during the follow-up.

Conclusion

The intracardiac atrial signal amplitudes were higher in congenital CHB compared with the acquired CHB. Chronicity (and may be the congenital type) of CHB may be an affecting factor in case selection for VDD pacemaker implantation.     

Assessment of the Correlation Between Two Defining Criteria for Bidirectional Isthmic Block in the Ablation of Typical Atrial Flutter

Background

A complete, bidirectional conduction block in the cavotricuspid isthmus (CTI) represents the end-point of the typical atrial flutter ablation. We investigated the correlation between two criteria for successful ablation, one based on the atrial bipolar electrogram morphology before and after complete CTI conduction block, compared to the standard criteria of differential pacing and reversal in the right atrial depolarization sequence during coronary sinus (CS) pacing.

Method

We conducted a retrospective study in 111 patients (81 males, average age 62±10 years) who underwent an atrial flutter ablation during September 2007 - July 2009 in the Cardiology - Rehabilitation Hospital, UMF Cluj-Napoca. We assessed the presence of a bidirectional block at the end of the procedure using the standard criteria. We then analyzed the morphology of the bipolar atrial electrograms adjacent to the ablation line, before and after CTI conduction block.

Results

A change from a qRs morphology to a rSr'' morphology when pacing from the coronary sinus and from a rsr'' morphology to a QRS morphology when pacing from the low-lateral right atrium was associated with a CTI conduction block. Sensitivity (Se), specificity(Sp), positive predictive value (PPV), negative predictive value (NPV) were 96%, 89%, 99% and 67% respectively.

Conclusion

Our study suggests that the analysis of the atrial bipolar electrogram next to the ablation line before and after CTI ablation may be used as a reliable criterion to validate CTI conduction block due to its high sensitivity, specificity and positive predictive value.     

Predictors of postoperative atrial fibrillation after coronary artery bypass graft surgery

Objectives

The present study was aimed to identify the preoperative, intraoperative, and postoperative predictors of AF in a pure cohort of the patients with coronary artery disease who underwent CABG surgery.

Methods

Between November 2005 and May 2006, 302 consecutive patients were included in this prospective study. All the relevant clinical, electrocardiographic, echocardiographic, and laboratory data were gathered in the included patients and they were also monitored for development of post-CABG AF.

Results

Postoperative AF occurred in 46 (15%) of patients. By univariate analysis, older age, P-wave abnormality in ECG, presence of mitral regurgitation, larger left atrium (LA), left main coronary artery involvement, failure to graft right coronary artery (RCA), and adrenergic use in ICU were significantly associated with occurrence of post-CABG AF (all P< 0.05). However, in the logistic regression model, age (OR: 1.067, 95%CI: 1.02-1.116, P=0.005), LA dimension (OR: 1.102, 95%CI: 1.017-1.1936, P=0.017), P-wave morphology (OR: 12.07, 95%CI: 3.35-48.22, P=0.0001), failure to graft RCA (OR: 3.57, 95%CI: 1.20-10.64, P=0.022), and postoperative adrenergic use (OR: 0.35, 95%CI: 0.13-0.93, P=0.036) remained independently predictive of postoperative AF.

Conclusion

The present study suggested that age, P-wave morphology, LA dimension, failure to graft right coronary artery, and postoperative adrenergic use were independent predictors of post-CABG AF. Therefore, clinical data, ECG and echocardiography may be useful in preoperative risk stratification of the surgical patients for the occurrence of post-CABG AF.     

Malignant arrhythmia in apical ballooning syndrome: risk factors and outcomes

Objectives

We sought to determine the frequency and outcomes with symptomatic arrhythmia in patients with apical ballooning syndrome (ABS).

Methods

A retrospective review of the Mayo Clinic Angiography database was conducted to identify patients who met the Mayo criteria for ABS. Patients with documented arrhythmias formed the study group, and 31 randomly selected patients with ABS but without arrhythmia formed the control group.

Results

Out of 105 patients identified with ABS, 6 (5.7%) women aged 69 +/- 9 years experienced significant arrhythmia (ventricular fibrillation, asystole), 2 patients died, and 1 required permanent pacemaker implantation. When compared with controls, the study group showed no significant difference with respect to ECG characteristics (QT, QRS duration or axis) except for R-R interval variability (see comments below) (30.6±6 vs 14.5±17 p = 0.0004), QTc, and P-R interval. Patients without arrhythmia were more likely to be on beta-blocker therapy than the study population (33% vs 80.6% p = 0.02).

Conclusion

Life-threatening arrhythmia is uncommon (5.7%) with ABS despite marked, structural abnormalities. When arrhythmias do occur, the outcome is poor. Prominent variability in R-R intervals appears to be predictive of significant arrhythmias in ABS. The role of beta-blocker therapy in preventing arrhythmia with ABS requires further investigation.     

Non-ischemic cardiomyopathy patients derive superior mortality benefit from cardiac resynchronization therapy

Background

Cardiac Resynchronization Therapy (CRT) is indicated for the treatment of advanced heart failure with severe systolic dysfunction and intraventricular conduction delay. Patient selection for this technology is vital, though it remains unclear which patients benefit most from CRT. We tested the hypothesis that patients with non-ischemic cardiomyopathy have a superior mortality benefit from CRT than ischemic cardiomyopathy patients.

Methods

We evaluated 95 CRT patients to determine which factors predict mortality.

Results

Patients with non-ischemic cardiomyopathy had a significantly better prognosis than patients with ischemic cardiomyopathy.

Conclusion

Larger prospective studies can substantiate this finding and better delineate which patients benefit most from CRT.     

Orthogonal P-wave morphology is affected by intra-atrial pressures

Background

It has previously been shown that the morphology of the P-wave neither depends on atrial size in healthy subjects with physiologically enlarged atria nor on the physiological anatomical variation in transverse orientation of the left atrium. The present study aimed to investigate if different pressures in the left and right atrium are associated with different P-wave morphologies.

Methods

38 patients with isolated, increased left atrial pressure, 51 patients with isolated, increased right atrial pressure and 76 patients with biatrially increased pressure were studied. All had undergone right heart catheterization and had 12-lead electrocardiographic recordings, which were transformed into vectorcardiograms for detailed P-wave morphology analysis.

Results

Normal P-wave morphology (type 1) was more common in patients with isolated increased pressure in the right atrium while abnormal P-wave morphology (type 2) was more common in the groups with increased left atrial pressure (P = 0.032). Moreover, patients with increased left atrial pressure, either isolated or in conjunction with increased right atrial pressure, had significantly more often a P-wave morphology with a positive deflection in the sagittal plane (P = 0.004).

Conclusion

Isolated elevated right atrial pressure was associated with normal P-wave morphology while left-sided atrial pressure elevation, either isolated or in combination with right atrial pressure elevation, was associated with abnormal P-wave morphology.

     

Pacemaker Dependency after Cardiac Surgery: A Systematic Review of Current Evidence

Background

Severe postoperative conduction disturbances requiring permanent pacemaker implantation frequently occur following cardiac surgery. Little is known about the long-term pacing requirements and risk factors for pacemaker dependency in this population.

Methods

We performed a systematic review of the literature addressing rates and predictors of pacemaker dependency in patients requiring permanent pacemaker implantation after cardiac surgery. Using a comprehensive search of the Medline, Web of Science and EMBASE databases, studies were selected for review based on predetermined inclusion and exclusion criteria.

Results

A total of 8 studies addressing the endpoint of pacemaker-dependency were identified, while 3 studies were found that addressed the recovery of atrioventricular (AV) conduction endpoint. There were 10 unique studies with a total of 780 patients. Mean follow-up ranged from 6–72 months. Pacemaker dependency rates ranged from 32%-91% and recovery of AV conduction ranged from 16%-42%. There was significant heterogeneity with respect to the definition of pacemaker dependency. Several patient and procedure-specific variables were found to be independently associated with pacemaker dependency, but these were not consistent between studies.

Conclusions

Pacemaker dependency following cardiac surgery occurs with variable frequency. While individual studies have identified various perioperative risk factors for pacemaker dependency and non-resolution of AV conduction disease, results have been inconsistent. Well-conducted studies using a uniform definition of pacemaker dependency might identify patients who will benefit most from early permanent pacemaker implantation after cardiac surgery.     

Predictors and frequency of conduction disturbances after open-heart surgery

Introduction

The risk of developing conduction disturbances after coronary bypass grafting (CABG) or valvular surgery has been well established in previous studies, leading to permanent pacemaker implantation in about 2% to 3% of patients, and in 10% of patients undergoing repeat cardiac surgery. We sought to determine the incidence, features and predictors of conduction disorders in the immediate post-operative period of patients subjected to open-heart surgery, and the need for permanent pacemaker implantation.

Material and Method

We prospectively studied 374 consecutive patients who underwent open-heart surgery in our institution: coronary artery bypass (CABG) (n=128), Mitral valve replacement(MVR)(n=18), aortic valve replacement(AVR) (n=21), MVR and AVR(n=56), repair of ventricular septal defect (VSD) (n=51), repair of tetralogy of Fallot (TOF) (n=57),CABG and valvular surgery (n=6), others (n=37).

Results

Among 374 patients included in our study (mean age 34.46±25.68; 146 males), 192 developed new conduction disorders: symptomatic sinus bradycardia in 8%, atrial fibrillation with slow ventricular response (AF) in 4.5%, first-degree atrioventricular block (AVB)in 6.4%, second-degree AVB in 0.3%, third-degree AVB in 7%, new right bundle branch block (RBBB) in 33%, and new left bundle branch block (LBBB) in 2.1%. In 5.6% patients, a permanent pacemaker was implanted, 47.6% of them underwent valvular surgery. In 44.1% of patients the conduction defects occurred in the first 48 hr. after surgery. In CABG group, 29.7% of patients developed new conduction disturbances; the most common of them was symptomatic sinus bradycardia. After valvular surgery 44.2% of patients developed conduction disturbances, of those the most common was atrial fibrillation with slow ventricular response . After VSD and TOF repair, the most common conduction disturbance was new RBBB. Perioperative myocardial infarction (MI) occurred in 1.9% of patients. The occurrence conduction disturbance was compared with patient age, sex, occurrence of perioperative MI, ejection fraction (EF), postoperative use of ß-adernergic receptor blocking agents and digitalis and type of cardiac surgery. By regression analysis there was a correlation between type of surgery and new conduction defects, being significant for CABG and TOF repair. Only the occurrence of perioperative MI was related to PPM implantation.

Conclusion

Irreversible AVB requiring a PPM is an uncommon complication after open-heart surgery. Peri-operative MI is a risk factor.     

Isthmus Dependent Atrial Flutter Cycle Length Correlates with Right Atrial Cross-Sectional Area

Background

Right atrial flutter cycle length can prolong in the presence of antiarrhythmic drug therapy. We hypothesized that the cycle length of right atrial isthmus dependent flutter would correlate with right atrial cross-sectional area measurements.

Methods

60 patients who underwent ablation for electrophysiologically proven isthmus dependent right atrial flutter, who were not on Class I or Class III antiarrhythmic drugs and had recent 2-dimensional echocardiographic data comprised the study group. Right atrial length and width were measured in the apical four chamber view. Cross-sectional area was estimated by multiplying the length and width. 35 patients had an atrial flutter rate ≥ 250 bpm (Normal Flutter Group) and 25 patients had an atrial flutter rate < 250 bpm (Slow Flutter Group).

Results

Mean atrial flutter rate was 283 bpm in the normal flutter group and 227 bpm in the slow flutter group. Mean atrial flutter cycle length was 213 ms in the Normal Flutter Group and 265 ms in the Slow Flutter Group (p< 0.0001). Mean right atrial cross sectional area was 1845 mm² in the Normal Flutter group and 2378 mm² in the Slow Flutter Group, (p< 0.0001). Using linear regression, CSA was a significant predictor of cycle length (β =0.014 p = 0.0045). For every 1 mm² increase in cross-sectional area, cycle length is 0.014 ms longer.

Conclusions

In the absence of antiarrhythmic medications, right atrial cross sectional area enlargement correlates with atrial flutter cycle length. These findings provide further evidence that historical rate-related definitions of typical isthmus dependent right atrial are not mechanistically valid.     

The effect of ranolazine on maintaining sinus rhythm in patients with resistant atrial fibrillation

Background

Atrial fibrillation (AF) may arise out of anomalous impulse activity at atrial venous junctions. Triggered activity may be a source of abnormal impulse activity. Ranolazine is an anti-anginal agent, which inhibits normal and abnormal late Na+ channel current in the ventricle and peak Na+ channel current in the atrium. This produces an energy sparing effect and stabilizes cardiac membranes. Ranolazine is a potent inhibitor of triggered activity. The purpose of this report is to describe our initial experience with ranolazine used in patients with resistant AF.

Methods

Seven patients (4 males, 3 females, 67 ± 9 years) who developed recurrent AF within hours to a few days of restoring sinus rhythm despite AF ablation and /or failing one or more anti-arrhythmic agents were started on ranolazine (500-1000 mg/twice/day) after stopping all other anti-arrhythmic therapy. All but one patient had some form of associated structural heart disease.

Results

Two patients received no apparent benefit from ranolazine developing recurrent AF within 2 days. All other patients derived significant benefit. Four patients have experienced no recurrent AF. The other patient relapsed at 3 months and again at 6 months. The mean time in sinus rhythm to date, or to the first relapse, for the five responders was 27 ± 11 weeks. No clinically evident pro-arrhythmic episodes occurred.

Conclusion

Ranolazine was helpful in maintaining sinus rhythm in the majority of patients in which more established measures had failed. A controlled prospective trial is warranted to further investigate the efficacy of ranolazine in AF.     

Anodal stimulation: an underrecognized cause of nonresponders to cardiac resynchronization therapy

Objective

The purpose of this study was to determine if anodal stimulation accounts for failure to benefit from cardiac resynchronization therapy (CRT) in some patients.

Background

Approximately 30-40% of patients with moderate to severe heart failure do not have symptomatic nor echocardiographic improvement in cardiac function following CRT. Modern CRT devices allow the option of programming left ventricular (LV) lead pacing as LV tip to right ventricular (RV) lead coil to potentially improve pacing thresholds. However, anodal stimulation can result in unintentional RV pacing (anode) instead of LV pacing (cathode).

Methods

Patients enrolled in our center''s CRT registry had an echocardiogram, 6-minute walk (6MW), and Minnesota Living with HF Questionnaire (MLHFQ) pre-implant and 6 months after CRT. Electrocardiograms (12 lead) during RV, LV, and biventricular (BiV) pacing were obtained at the end of the implant in 102 patients. Anodal stimulation was defined as LV pacing QRS morphology on EKG being identical to RV pacing or consistent with fusion with RV and LV electrode capture. LV end systolic volume (LVESV) was measured by echo biplane Simpson''s method and CRT responder was defined as 15% or greater reduction in LVESV.

Results

Of the 102 patients, 46 (45.1%) had the final LV lead pacing configuration programmed LV (tip or ring) to RV (coil or ring). 3 of the 46 subjects (6.5%) had EKG findings consistent with anodal stimulation, not corrected intraoperatively. All anodal stimulation patients were nonresponders to CRT by echo criteria (reduction in LVESV 13.3 ± 0.6%, increase in EF 5.0 ± 1.4%) compared to 46% responders for those without anodal stimulation, (change in LVESV 18.7 ± 25.6%, EF 7.6 ±10.9%). None of the anodal stimulation patients were responders for the 6 minute walk, compared to 32 of 66 (48%) of those without anodal stimulation.

Conclusion

Anodal stimulation is a potential underrecognized and ameliorable cause of poor response to CRT.     

Normal Heart Ventricular Tachycardia Associated with Pregnancy: Successful Treatment with Catheter Ablation

Background

Normal heart ventricular arrhythmia occurring during pregnancy has been previously described. Whilst there are established reports of catheter ablation to treat supraventricular arrhythmia during pregnancy, there are no reports of ablation to treat ventricular tachycardia.

Case

We present the case of a 36 year old women, 31 weeks into an otherwise uncomplicated pregnancy, experiencing significant, troublesome and drug refractory tachycardia emanating from the right ventricular outflow tract.

Conclusion

We describe a successful radio frequency ablation in the third trimester of pregnancy.     

Gene Expression of ANP,BNP and ET-1 in the Heart of Rats during Pulmonary Embolism

Aims

Atrial natriuretic petide (ANP), brain natriuretic peptide (BNP) and endothelin-1 (ET-1) may reflect the severity of right ventricular dysfunction (RVD) in patients with pulmonary embolism (PE). The exact nature and source of BNP, ANP and ET-1 expression and secretion following PE has not previously been studied.

Methods and Results

Polystyrene microparticles were injected to induce PE in rats. Gene expression of BNP, ANP and ET-1 were determined in the 4 cardiac chambers by quantitative real time polymerase chain reaction (QPCR). Plasma levels of ANP, BNP, ET-1 and cardiac troponin I (TNI) were measured in plasma. PE dose-dependently increased gene expression of ANP and BNP in the right ventricle (RV) and increased gene expression of ANP in the right atrium (RA). In contrast PE dose-dependently decreased BNP gene expression in both the left ventricle (LV) and the left atrium (LA). Plasma levels of BNP, TNI and ET-1 levels dose-dependently increased with the degree of PE.

Conclusion

We found a close correlation between PE degree and gene-expression of ANP, and BNP in the cardiac chambers with a selective increase in the right chambers of the heart.The present data supports the idea of natriuretic peptides as valuable biomarkers of RVD in PE.     

Initial experience of a cohort of patients with hypertrophic cardiomyopathy undergoing biventricular pacing

Background

Dual chamber pacing improves functional status and reduces left ventricular outflow tract gradients in some, but not all patients with hypertrophic cardiomyopathy (HCM) by altering ventricular depolarisation. We investigated the use of biventricular (BIV) pacing in symptomatic patients with HCM.

Method

8 patients aged 58±7yrs with symptomatic HCM underwent BIV pacing. 5 patients had LVOT gradients >30mmHg. Ventricular electrodes were placed in the right ventricle (RV) and a branch of the coronary sinus. An atrial electrode was inserted to achieve BIV pacing with a short AV delay. The short-term effects of different pacing modalities were assessed using 2-D and Doppler echocardiography. Symptoms and exercise tolerance were assessed after a month of each pacing mode. Long-term follow up data was available for 5 years.

Results

Baseline EF was 67±14% and mean QRS duration was 132±26msecs. BIV pacing reduced QRS duration compared to RV pacing (129±46 vs. 205±54msecs, p<0.005). Five of the seven patients had baseline LVOT gradients (mean 67±25mmHg) that decreased to 41±15mm Hg with RV pacing (p<0.01) and 25±15mmHg with BIV pacing (p<0.005). Improvements in exercise time with active pacing occurred in six out of eight patients (75%), three (37.5%) had optimal exercise times with RV pacing and three with BIV pacing. Of the three patients with short term improvements with BIV pacing, one died 4 years post implant, one deteriorated with LV dilatation and one had the system explanted for infection.

Conclusion

BIV pacing showed short-term beneficial effects in some patients over and above RV pacing alone.     

Msx1 Gene Variant - its Association in Isolated Hypodontia: A Case Control Genetic study!!!

INTRODUCTION:

Non-syndromic tooth agenesis is a congenital anomaly with significant medical, psychological, and social ramifications. There is sufficient evidence to hypothesize that locus for this condition can be identified by candidate genes.

AIM OF THE STUDY:

The aim of this study was to test whether MSX1 671 T > C gene variant was involved in etiology of non-syndromic tooth agenesis in Raichur patients.

MATERIALS AND METHODS:

Blood samples were collected with informed consent from 50 subjects having non-syndromic tooth agenesis and 50 controls. Genomic deoxyribonucleic acid (DNA) was extracted from the blood samples, polymerase chain reaction (PCR) was performed, and restriction fragment length polymorphism (RFLP) was performed for digestion products that were evaluated.

RESULTS:

The results showed positive correlation between MSX1671 T > C gene variant and non-syndromic tooth agenesis in Raichur patients.

CONCLUSION:

MSX1 671 T > C gene variant may be a good screening marker for non-syndromic tooth agenesis in Raichur patients.     

Karyotypic findings in chronic myeloid leukemia cases undergoing treatment

BACKGROUND:

Chronic myeloid leukemia (CML) is a clonal myeloproliferative expansion of primitive hematopoietic progenitor cells.

MATERIALS AND METHODS:

In the present study, CML samples were collected from various hospitals in Amritsar, Jalandhar and Ludhiana.

RESULTS:

Chromosomal alterations seen in peripheral blood lymphocytes of these treated and untreated cases of CML were satellite associations, double minutes, random loss, gain of C group chromosomes and presence of marker chromosome. No aberrations were observed in control samples. Karyotypic abnormalities have also been noted in the Ph-negative cells of some patients in disease remission.

CONCLUSION:

This is a novel phenomenon whose prognostic implications require thorough and systematic evaluation.