Browsing by Author "Namboodiri, Narayanan"

Now showing 1 - 20 of 26
  • Item
    A Rare Type of Dual Left Anterior Descending Artery Distribution Demonstrated by Multislice Cardiac Computerized Tomography in a Patient with Anterior Wall Infarction
    (JOURNAL OF INVASIVE CARDIOLOGY, 2008)
    Dual left anterior descending coronary artery (LAD) distribution with either of the vessels originating from the left main coronary artery (LMCA) and the right aortic sinus of Valsalva is an extremely rare coronary artery anomaly. Here we discuss a 45-year-old male who presented with non-ST-elevation anterior wall myocardial infarction due to near-total occlusion of the LAD immediately after its origin from the LMCA. The distal interventricular septum was supplied by an additional LAD arising from the right aortic sinus with a long septal course. The anomalous origin and septal course of the latter vessel were confirmed with multislice cardiac computerized tomography. The binary distribution of the LAD limited the extent of ischemic insult to the anterior wall in this case.
  • Item
    Ablation of Ventricular Arrhythmias in GUCH: The Surgical Scar and the Second Substrate.
    (Indian pacing and electrophysiology journal, 2012)
  • Item
    An unusual mechanism of sustained right atrial tachycardia.
    (Indian pacing and electrophysiology journal, 2011)
    Lower loop re-entry (LLR) flutter is a rare type of atypical right atrial flutter. Most of the reported cases occurred in association with typical flutter patterns as a transient arrhythmia. Our case is unique in the fact the LLR was sustained and persisted independently.
  • Item
    Bradycardia-induced Torsade de Pointes - An arrhythmia Less Understood.
    (Indian pacing and electrophysiology journal, 2010)
  • Item
    Bundle branch reentry ventricular tachycardia in arrhythmogenic right ventricular dysplasia
    (JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY, 2008)
    A 42-year-old male had history of recurrent palpitation and was documented to have wide QRS tachycardia. Magnetic resonance imaging angiogram showed evidence of arrhythmogenic right ventricular dysplasia and severe right ventricular dysfunction. Electrophysiology study showed evidence of bundle branch reentry ventricular tachycardia. It was successfully treated by radiofrequency ablation of right bundle branch. This is probably the first case of bundle branch reentry as a mechanism for ventricular tachycardia in a case of arrhythmogenic right ventricular dysplasia.
  • Item
  • Item
    Dilated Cardiomyopathy with Short QT Interval: Is It a New Clinical Entity?
    (PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY, 2009)
    Short QT syndrome is a rare autosomal dominant channelopathy of structurally normal hearts characterized by atrial fibrillation, ventricular arrhythmias, and sudden cardiac death. We report a case having short QT, dilated ventricles, and severe ventricular dysfunction, an unreported association so far. (PACE 2009; 32:688-690)
  • Item
    Doppler echocardiographic assessment of TTK Chitra prosthetic heart valve in the mitral position
    (EUROPEAN JOURNAL OF ECHOCARDIOGRAPHY, 2008)
    Aims TTK Chitra heart valve prosthesis (CHVP), a tilting disc mechanical heart valve of tow cost and proven efficacy, has been in use for the last 15 years. Although various studies substantiating its long-term safety and efficacy are available, no study had assessed its echocardiographic characteristics. The purpose of this study was to determine the normal Doppler parameters of CHVP in the mitrat position and to assess whether derivation of mitrat valve area (MVA) using the continuity equation (CE) and more commonly used pressure half-time (PHT) method is comparable in the functional assessment of this tilting disc mitral prosthesis.Methods and results Doppler echocardiography was performed in 40 consecutive patients with CHVP in the mitrat position. All patients were clinically stable, without evidence of prosthetic valve dysfunction such as significant obstruction or regurgitation, enclocarditis, left ventricular dysfunction (ejection fraction <40%), or significant aortic regurgitation. Valve sizes studied included 25, 27, and 29 mm. Mitrat valve area was derived both by the PHT method and by the CE, using the stroke volume measured in the ventricular outflow tract divided by the time-velocity integral of CHVP jet. The peak Doppler gradient ranged from 5 to 21 (mean 11.0) mmHg, and the mean gradient ranged from 1.7 to 9.2 (mean 4.1) mmHg. Mean gradient negatively correlated with an increase in the actual orifice area (ACA) derived from the valve orifice diameter given by the manufacturer (r = -0.45, P = 0.004). Mitral valve area calculated by both PHT and CE increased significantly with an increase in the ADA (r = 0.42, P = 0.007 and r = 0.32, P = 0.046, respectively). Mitrat valve area by the CE averaged 1.55 +/- 0.36 cm(2) (range 0.85 cm(2) for a 25 mm valve to 2.41 cm(2) for a 29 mm valve) and was smaller than by PHT (mean 2.04 +/- 0.41 cm(2), range 1.40-3.14 cm(2); P = 0.0001; t-test), irrespective of whether PHT is less than or >110 ms.Conclusion The Doppler parameters obtained with CHVP in the mitrat position are comparable with those obtained with the different prosthetic valves in common use. In the selected group of patients with CHVP, assessment of MVA by the PHT method is comparable with that by the CE. Areas by both methods were smaller than the AOA provided by the manufacturer, as seen in other similar design valves.
  • Item
  • Item
    Electrophysiology study and radiofrequency catheter ablation of atriofascicular tracts with decremental properties (Mahaim fibre) at the tricuspid annulus
    (EUROPACE, 2008)
    Aims The aim was to study the common mapping methods for Mahaim fibre and their role in radiofrequency ( RF) ablation.Methods and results Fifteen patients having Mahaim fibre tachycardia underwent electrophysiological study. Mahaim fibre mapping methods like (i) Mahaim potential ( M), (ii) shortest atrial stimulus-to-preexcitation (STP), and (iii) mechanical trauma induced loss of conduction were studied. Accessory pathway mapping was performed by M potential in 10 patients (67%), shortest atrial STP in 3 patients (20%), and mechanical trauma in 2 patients (13%). Mahaim fibre was localized at right atrial freewall of tricuspid annulus (8-10 o'clock) in 13 patients (87%), at 6.30 o'clock in one patient, and at 5 o'clock in 1 patient. Fourteen patients underwent RF ablation. Thirteen patients had complete loss of conduction over accessory pathway and one had partial modi. cation with a conduction delay. Radiofrequency ablation was not performed in one patient ( shortest STP group) due to its closeness to the compact atrioventricular node. Mahaim junctional acceleration during RF ablation was observed in all patients of M potential, 1 patient of mechanical trauma, and none of the atrial STP group. One patient ( M potential group) had tachycardia recurrence during follow-up.Conclusion Mahaim fibre is commonly located between 8 and 10 o'clock at tricuspid annulus. M potential guides to successful RF ablation in most patients. Mahaim junctional acceleration is commonly seen during RF ablation guided by M potential map.
  • Item
    Intra-atrial extension of Wilms' tumor.
    (Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography, 2008)
    Echocardiography in a 4-year-old boy, with nephroblastoma of the left kidney, revealed a large homogenous mass in right atrium extending from inferior vena cava, and protruding through tricuspid valve into right ventricle during diastole. Ultrasonography revealed the contiguous spread of the tumor through renal vein with near total caval occlusion. The patient had a fatal outcome before definite treatment could be started. Intracardiac extension of infradiaphragmatic tumors through caval route, although infrequent, can be seen with renal cell carcinoma, Wilms' tumor, hepatoma, lymphoma, and uterine and adrenal tumors. Detection of a mass in right atrium in a child should alert the echocardiographer about the possibility of caval spread from a renal neoplasm.
  • Item
    Late presentation of aortic root abscess in endocarditis with coronary ischemia.
    (Asian cardiovascular & thoracic annals, 2009)
    Formation of a large aortic root abscess is an infrequent complication of aortic valve endocarditis in adults. Extrinsic compression of the coronary arteries by this abscess is still rarer. Here, we report a case of a 22-year-old male with aortic root abscess, who presented 2 months after the completion of treatment of endocarditis with exertional angina. Coronary angiogram revealed compression of proximal left anterior descending and left circumflex arteries by the abscess. The patient was successfully treated with pericardial patch exclusion of the abscess cavity and coronary artery bypass graft. The presentation of aortic root abscess with myocardial ischemia as a late complication of treated endocarditis has not been reported earlier.
  • Item
    Mahaim fiber accelerated automaticity and clues to a mahaim fiber being morphologically an ectopic or a split AV node.
    (Indian pacing and electrophysiology journal, 2010)
    Mahaim Fiber tachycardia characteristically causes a wide QRS tachycardia with left bundle branch morphology and left axis deviation, especially in young patients, having no structural heart disease. Mahaim fiber automaticity further cements the proposition of Mahaim fiber, due to its Atrioventricular (AV) node like property, being called as an ectopic AV node.
  • Item
    Narrow Complex Tachycardia with Ventriculoatrial Dissociation-What is the Mechanism?
    (PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY, 2011)
  • Item
    Natural History of Aortic Valve Disease Following Intervention for Rheumatic Mitral Valve Disease
    (JOURNAL OF HEART VALVE DISEASE, 2009)
    Background and aim of the study: A significant proportion of patients who require interventions for rheumatic mitral valve (MV) disease have coexisting aortic valve (AV) disease. To date, little is known of the natural history of AV disease in these patients.Methods: The details of a cohort of 200 patients (146 females, 54 males; mean age at MV intervention 30.3 +/- 9.9 years) with rheumatic heart disease were retrospectively reviewed. The patients had undergone an index MV intervention (either closed or balloon mitral valvotomy) or MV replacement between 1994 and 1996, and received long-term regular follow up examinations. The clinical and echocardiographic data at entry and at follow up were noted. Patients were allocated to two groups, based on whether the AV disease was absent (group I, n = 98) or present (group 11, n = 102) at baseline. The AV disease was categorized as thickening only (group IIA), isolated aortic regurgitation (AR) (group IIB), or combined aortic stenosis (AS) and AR (group IIC). No patient had isolated AS at baseline.Results: The mean follow up period was 9.3 +/- 1.07 years, during which 10 patients in group I developed new AV disease, which included AV thickening only (n = 2), trivial-mild AR (n = 7) and mild AS with trivial AR (n = 1). Of 16 patients in group IIA, 11 developed isolated AR, and one patient progressed to have mild AS and AR. Among 69 patients in group IIB, 22 (31.9%) developed AS, and all had either mild (n = 8) or moderate (n = 14) AR with mild AS. Group IIC included 17 patients with mild combined AV disease at baseline, except for moderate AS and moderate AR in one patient each. Among 16 patients with mild AS in group IIC, six progressed to moderate AS and two to severe AS. AR became moderate in 10 patients and severe in one patient. The two patients who progressed to severe AS requiring AV replacement had mild AS at baseline. No patient who developed new combined AV disease had lesions with severity more than mild AS or moderate AR. On logistic regression analysis of the variables predisposing to progression of AV disease, such as age, gender, history of rheumatic fever (RF) and recurrence, and interval from RF episode to symptom onset, only the initial AV gradient was identified as being statistically significant (beta coefficient 0.528, SE = 0.17, p < 0.0001).Conclusion: Patients with no or mild AV disease at the time of MV intervention rarely develop severe AV disease, and seldom require AV surgery over the long-term follow up. The presence of mild AS at baseline is predictive in the minority of cases where AV disease will progress relatively more rapidly.
  • Item
    Percutaneous closure of ruptured sinus of Valsalva aneurysms: intermediate term follow-up results
    (EUROINTERVENTION, 2010)
    Aims: Surgical repair used to be the conventional treatment of ruptured sinus of Valsalva aneurysms (RSOVA). Recently many articles have described the percutaneous closure of these defects. We report the successful percutaneous closure of seven cases of RSOVA.Methods and results: All the procedures were done under local anaesthesia with fluoroscopic and echocardiographic guidance. The defects were closed with nitinol ductal occluders introduced from the venous side after the establishment of an arteriovenous loop. Of the seven patients (four males, mean age 44.8 +/- 11 years), six had rupture of the congenital sinus of Valsalva aneurysm, and one had a recurrence following surgical repair. Out of the six patients with aneurysms of the right aortic sinus, four had rupture into the right atrium, one into the right ventricular (RV) inflow and the other into RV outflow. One patient had non-coronary sinus aneurysm rupturing into the right atrium. The size of the distal opening of the aneurysm varied from 2.5 to 12 mm. The left to right shunt flow ratio (Qp/Qs) ranged from 1.5 to 3.6. The size of the nitinol ductal occluders used to close the defects varied from 4 to 16 mm. After a mean follow-up period of 9.3 +/- 3 months, all patients remained asymptomatic with no residual flow, aortic valvar insufficiency, or evidence of infection.Conclusions: RSOVAs can be safely and effectively closed percutaneously using nitinol ductal occluders.
  • Item
    Percutaneous mitral commissurotomy in a case of mirror-image dextrocardia and rheumatic mitral stenosis.
    (The Journal of invasive cardiology, 2008)
    A 43-year-old male with mirror-image dextrocardia and severe rheumatic mitral stenosis was subjected to successful percutaneous transvenous mitral commissurotomy (PTMC). The standard Inoue technique was modified by transseptal catheterization via the left femoral vein, image inversion, delineation of the interatrial septal anatomy via levophase pulmonary angiography, septal contrast staining and pigtail catheter insertion in the noncoronary aortic sinus, interatrial septal puncture with the transseptal needle rotated to a 7 o'clock position and left ventricular entry with a reverse loop technique. There were no procedural complications. Intracardiac pressures and mitral valvular planimetry suggested a successful procedural outcome. This case illustrates that PTMC can be accomplished safely in patients with this unusual cardiac anatomy with a few modifications in the standard technique.
  • Item
    Single coronary artery from right aortic sinus with septal course of left anterior descending artery and left circumflex artery as continuation of right coronary artery: a hitherto unreported coronary anomaly.
    (The Journal of invasive cardiology, 2007)
    A single coronary artery (SCA) in the absence of structural heart disease is a rare coronary anomaly and is often detected incidentally during coronary angiography. We report a hitherto undescribed type of SCA originating from the right sinus of Valsalva, with the left anterior descending artery having a septal course and the right coronary artery continuing as the left circumflex artery, which was incidentally detected in a 73-year-old female.
  • Item
    Subannular left ventricular pseudoaneurysm following mitral valve replacement
    (JOURNAL OF CARDIOTHORACIC SURGERY, 2008)
    Delayed development of left ventricular pseudoaneurysm is a rare late complication of mitral valve prosthesis and requires early surgical intervention. Here we describe the occurrence of such a complication diagnosed 6-months after the valve surgery in a 60-year-old lady. The anatomic delineation of subannular left ventricular pseudoaneurysm using multiple imaging modalities including CT angiography is also being discussed.
  • Item
    Tako-tsubo cardiomyopathy in a patient with myasthenia gravis crisis: a rare clinical association.
    (BMJ case reports, 2009)
    Tako-tsubo cardiomyopathy (TTC) is increasingly being recognised as transient left ventricular dysfunction following various hyperadrenergic states such as emotional or physical stressors. The association of this rare clinical entity with myasthenia gravis (MG) has been reported only twice in the literature, both following plasmapheresis for MG crisis. Here we describe a unique case of TTC in a 40-year-old woman with MG admitted with MG crisis managed conservatively. This case suggests that plasmapheresis is unlikely to have a causative role in the development of TTC in these patients. Patients with MG crisis may be at potential risk of developing TTC and careful clinical and electrocardiographic monitoring is necessary while treating them. The possible role of stress as the common precipitating factor in both conditions is also discussed.