Investigation of persistent hypochromic microcytosis unmasks hemoglobin Evanston [alpha 14 (A12) Try--> Arg] in a patient of cyclic thrombocytopenia preceding Takayasu's disease.

We report an unusual north Indian patient with Hemoglobin Evanston [alpha 14 (A12) Try --> Arg] who had acquired cyclic thrombocytopenia (10-1230 x 10(9)/l periodic oscillation of four week duration) which recovered without any specific therapy. She later developed Takayasu's disease and underwent three corrective stents. She is presently in clinical remission and is on regular follow up. To the best of our knowledge our patient is the first report of Hb Evanston from the indigenous population of India and highlights the need to look for point mutations in the alpha globin gene, which may interact with thalassemia or other hemoglobinopathies, in atypical cases. The association of these three disorders in our patient is possibly unrelated though an immune basis for the cyclic thrombocytopenia and Takayasu's disease is likely as seen in this report.

Re-use of explanted DDD pacemakers as VDD- clinical utility and cost effectiveness.

Re-use of DDD pulse generators explanted from patients died of unrelated causes is associated with an additional cost of two transvenous leads if implanted as DDD itself, and high rate of infection according to some studies. We studied the clinical and economical aspects of reutilization of explanted DDD pacemakers programmed to VDD mode. Out of 28 patients who received VDD pacemaker during the period, October 2000- September 2001 in the Department of Cardiology, PGIMER, Chandigarh, 5 poor patients were implanted with explanted DDD pulse generators programmed to VDD mode. Each implantation was planned and carried out according to a standard protocol. The age ranged from 45 to 75 (mean-61) years. The indications for pacing were complete heart block (4) and second degree AV block (1). The clinical profile, costs and complications, if any were noted and followed up at regular intervals. The results were compared with patients who received new DDD pulse generators during this period. The additional cost for the atrial lead was not required in these patients. None of these patients had any local site infection. Compared to the two-lead system, the single lead system provided more rapid implantation and minimized complications associated with placement of an atrial lead. The explanted DDD pacemaker can be safely reused as VDD mode with same efficacy in selected patient population. This is associated with lower cost and complications compared to reimplantation as DDD itself.

Single stage bilateral common carotid artery stenting in a patient of Takayasu arteritis.

Carotid angioplasty and stenting is increasingly becoming a safe and efficacious modality of treatment in the management of carotid artery stenosis. Although atherosclerosis is the predominant cause of this morbid disease, Takayasu arteritis assumes special importance in south east Asia. The diffuse nature of this disease with associated inflammation and scarring of the vessel make revascularisation difficult. We report a case of Takayasu arteritis in which a successful bilateral common carotid stenting was done in a single sitting.

A cardiac evoked response algorithm providing automatic threshold tracking for continuous capture verification: a single-center prospective study.

BACKGROUND: The AutoCapture algorithm as implemented in Regency and Microny pacemakers (Pacesetter Inc., Sylmar, CA, USA) provides beat-by-beat monitoring of capture based on proper detection of the evoked response, provides high output back-up pulse when loss of capture occurs, performs periodic threshold evaluations and acquires the capture threshold data in a time-based event counter for later retrieval. The safety and efficacy of this algorithm was prospectively evaluated at a tertiary care hospital of north India. METHODS AND RESULTS: Fifty-four patients (38 males, mean age 66+/-13 years) received a ventricular pacemaker model Regency SC+ with low polarization bipolar lead for high-grade atrioventricular block (n=42) and sick sinus syndrome (n=12). Evoked response and polarization signal were assessed initially at 24 hours postimplant, and follow-up measurements were systematically conducted at week 1 and months 1, 3 and 6. Further evaluation of eligible patients was performed at 6-monthly intervals. Lead implantation parameters were optimum in all patients. At 6 months, the algorithm was functional in 51 patients. The pacing threshold increased to 0.89+/-0.36 V (p<0.001) in the first month and stabilized thereafter. Significant saving of energy was accomplished by a constant output safety margin of 0.3 V instead of the traditional 100%. While the evoked response signal remained stable throughout the study period, the potential signal increased significantly from 0.6+/-0.7 mV to 1.0+/-0.6 mV (p<0.001) in the first month and remained steady subsequently. Back-up pacing in the event of exit block was confirmed in all 25 patients who underwent a 24-hour Holter test. Based on the suggested sense margins, ventricular undersensing was observed in 7 (28%) patients, the majority of whom had competitive cardiac rhythms. An elderly patient with pneumonic illness succumbed to pulmonary embolism at 6 months. CONCLUSIONS: This large single-center experience on AutoCapture demonstrates the success of this algorithm in low-energy ventricular pacing without compromising the patient's safety.

De novo stenting of descending thoracic aorta in Takayasu arteritis: intermediate-term follow-up results.

We report our intermediate-term follow-up results of de novo stenting of descending thoracic aorta in Takayasu arteritis. Six patients (5 males and 1 female) underwent aortoplasty and stenting (8 Wallstents were deployed in 6 patients). Aortoplasty was performed with conventional balloons in 5 patients and with an Inoue balloon in 1 patient. The mean diameter of the aorta increased from 5.36 +/- 0.62 mm to 13.91 +/- 1.8 mm after stenting while the peak systolic gradient was totally abolished in all cases. These results were significantly better than aortoplasty alone (p < 0.0001). Lower limb claudication improved in all patients. Hypertension was cured in 3 patients and improved in 3 patients. All patients were asymptomatic over 6Eth 30 months (mean, 22.8 +/- 4.0 months) follow-up. All patients underwent angiographic follow-up after 6 months. They continued to have an absence of gradient with excellent flow across the stents. A minimal intimal reaction was observed at the stent margins. On follow-up angiogram at 6 months, one of the patients was noted to have developed a small asymptomatic pseudoaneurysm at the lower margin of the stent, which gradually increased in size over the next year and was treated by percutaneous endovascular deployment of a Wallstent graft. Our series demonstrates the safety and efficacy of stent deployment in stenotic lesions of the aorta in Takayasu arteritis and proves that the results are superior to plain balloon aortoplasty alone. This is also the only study that demonstrates intermediate-term success by angiographic follow-up at 6 months.

A follow-up study of balloon angioplasty and de-novo stenting in Takayasu arteritis.

Percutaneous balloon angioplasty (PTBA) is a universally accepted mode of therapy for stenotic coronary and peripheral arterial lesions. To establish the role of PTBA and stent placement in patients with Takayasu's arteritis (TA), these procedures were performed in 20 patients with TA. All patients received steroids, aspirin and ticlodipine (for stent placement) prior to procedure. Angioplasty was carried in patients with symptomatic stenotic vessel of more than 70% of normal diameter or a peak systolic gradient of more than 50 mm across stenotic aortic lesion. Stenting was performed for ostial lesion, long segment lesion or incomplete relief of stenosis and dissection following angioplasty. Carotid angioplasty and stenting was performed in five patients, aortic angioplasty in nine patients, aortic angioplasty and stenting in four patients, renal angioplasty in three patients, renal angioplasty and stenting in two patients and subclavian angioplasty in two patients, subclavian, angioplasty and stenting in three patients and coronary angioplasty and stent placement in one patient. The procedure was successful in all but one patient. On following up, two patients with carotid stent placement had restenosis. A saccular aneurysm developed at the lower end of stent in one patient with aortic stent placement. The PTBA with or without stent placement is a safe and effective method for relief of stenotic lesion in patients with TA.

Takayasu arteritis in children and young indians.

Twenty four patients of Takayasu arteritis (TA) aged less than 18 years were studied over a period of 20 years (1978-98). There were 4 males and 20 females with a male:female ratio of 1:5. The mean age of presentation was 14 years and the disease had a mean onset of time 4+/-1.5 months prior to admission to the hospital. Hypertension was the commonest mode of presentation seen in 83% of patients. 16% patients had congestive heart failure. Left ventricular hypertrophy was present in 54% patients. Angiographic findings showed that abdominal aorta was the commonest segment of aorta that was involved (71% cases). Renal artery was involved in 75% cases. Treatment modalities included antihypertensive drugs in 19 patients, antitubercular drugs in 7 patients and steroids in 7 patients. Renal angioplasty was performed in 2 patients with excellent results. On follow up 2 patients died. The causes of mortality were renal failure and heart failure in one patient each. The clinical profile of young patients with TA is similar to that of adults with this disease.

Cardiac arrhythmias and silent myocardial ischemia during hemodialysis.

Cardiac arrhythmias are noted in a significant proportion of chronic renal failure (CRF) patients on hemodialysis (HD), and may contribute to cardiovascular mortality. A number of factors have been implicated in the genesis of these arrhythmias. The role of silent myocardial ischemia (SMI), however, has not been evaluated systematically. We prospectively studied 38 unselected CRF patients on regular HD by continuous Holter monitoring starting 24 hours before HD, lasting through the dialysis session and continued for 20 hours thereafter. The recordings were analyzed for frequency, timing and severity of supraventricular and ventricular arrhythmias and SMI as identified by ST-segment depression. Ventricular arrhythmias during HD were noted in 11 (29%) patients (group I), and were potentially life-threatening (Lown Class III and IVa) in 13%. The remaining 27 patients (group II) had no ventricular arrhythmias during HD. There was no difference in the age, sex ratio, duration of HD, blood pressure, fluctuations in weight, hematocrit, predialysis creatinine, sodium, potassium, calcium or inorganic phosphate levels between patients in the two groups. The number of patients with clinical ischemic heart disease was significantly greater in group I. SMI was noted in 72% and 33% of group I and II patients respectively (p = 0.026). 46% of those with and 25% of those without ST changes during HD developed ventricular arrhythmias during HD. Both SMI and ventricular arrhythmias were noted most frequently during the last hour of dialysis. Hypertension, diabetes mellitus and ischemic heart disease were observed more frequently amongst patients with SMI. Ventricular arrhythmias are detected in a significant proportion of CRF patients on HD. These are probably related to coronary artery disease since silent myocardial ischemia is also noted more frequently during HD in these patients. Further studies incorporating coronary angiography are needed in a larger number of patients to establish a definite causal relationship.

Increased plasma nitrite level in cardiac failure.

Increased Plasma Nitrite Level in Cardiac Failure. Nitric oxide is implicated in the pathogenesis of cardiac failure. Plasma nitrite level (an end product of nitric oxide metabolism) is studied in 15 patients of chronic rheumatic valvular heart disease with myocardial contractile dysfunction and cardiac failure (Group I), 15 patients of chronic rheumatic valvular heart disease with similar valvular lesions, normal myocardial contractile function and without cardiac failure (Group II) and 15 healthy controls (Group III). Patients in Group I had higher nitrite level (242.2+/-31.7 n m) compared to Group II (142.6+/-24.4 n m) and Group III (102.7+/-15.9 n m). Among the patients with rheumatic heart disease, increasing nitrite level correlated significantly with worsening of contractile function [Nitrite v End systolic volume/Body surface area (T(xy.z)=0.23), Nitrite v End systolic dimension/Body surface area (T(xy.z)=0.32), Nitrite v left ventricular ejection fraction (T(xy.z)=-0.24), Nitrite v tricuspid annular plane systolic excursion (T(xy.z)=-0. 29)] and worsening New York Heart Association (NYHA) functional class (r(s)=0.5). We conclude that plasma nitrite, a stable end product of nitric oxide metabolism is increased in patients of rheumatic valvular heart disease with cardiac failure, suggesting increased nitric oxide production. Increased level of nitric oxide might be playing a significant role in myocardial contractile dysfunction and alteration of vascular response in cardiac failure.

Autonomic functions in restrictive cardiomyopathy and constrictive pericarditis: a comparison.

BACKGROUND: This study was undertaken to analyze autonomic functions in restrictive cardiomyopathies. Restrictive cardiomyopathies have clinical and hemodynamic similarity with chronic constrictive pericarditis. Autonomic dysfunction has been described in the latter. METHODS AND RESULTS: Autonomic function analysis has not been reported in restrictive cardiomyopathy. Six consecutive patients with restrictive cardiomyopathy were included in this study (5 men, 1 woman, mean age 35+/-5.4 years). The tests performed were designed to test the sympathetic efferent pathway, that is, by cold hand immersion and loud noise tests, parasympathetic efferent pathway by Valsalva ratio and expiration/inspiration ratio and the baroreceptor function by testing their sensitivity slope. The results were compared with 20 patients with chronic constrictive pericarditis and with 10 healthy age- and sex-matched control subjects previously studied. The rise of systolic blood pressure after cold hand immersion and sudden loud noise was not significantly different compared with control subjects. The expiration/inspiration ratio was 1.1+/-0.01 compared with 1.57+/-0.1 in the control group (p < 0.01). The Valsalva ratio was significantly lower (1.1+/-0.04) compared with control subjects (1.83+/-0.1, p < 0.01). The baroreceptor sensitivity was not reduced compared with that in control subjects. In comparison to constrictive pericarditis, sympathetic efferent pathway is preserved in restrictive cardiomyopathy (p < 0.0001). The parasympathetic efferent pathway is borderline abnormal in restrictive cardiomyopathy but not significantly as compared with constrictive pericarditis (p=not significant). The baroreceptor sensitivity slope is normal in patients with restrictive cardiomyopathy as compared with significant depression seen in constrictive pericarditis (p < 0.05). Autonomic functions are better preserved in patients with restrictive cardiomyopathies compared with chronic constrictive pericarditis. CONCLUSIONS: Autonomic dysfunction is localized to parasympathetic efferent pathway. This is in comparison to constrictive pericarditis, in which severe autonomic dysfunction is a universal feature and includes all segments of autonomic nervous system.

Stent supported angioplasty in Takayasu arteritis.

Eleven patients with Takayasu Arteritis (TA) underwent angioplasty and stent placement in aorta, renal, carotid, subclavian and coronary arteries. Five wall stents were deployed in aorta in four patients. Indications for angioplasty and stent placement in aorta included hypertension in four patients and claudication and erectile impotence in one patient each. Post-procedure the peak systolic pressure gradient across the stenotic segment in the aorta disappeared. Six patients underwent angioplasty and stent placement in carotid arteries. Indications were syncope in 6 patients, loss of vision, stroke, transient ischaemic attack and seizures in one patients each. There was a marked improvement in symptoms in the patients following the procedure. For chronic total occlusion of subclavian arteries, two stents were deployed in two patients. Following the stent placement pulses in upper limb reappeared. Stents were also deployed to treat near total occlusion of right coronary artery and flow limited dissection of renal artery in one patient each. Complications of the procedure included pain in the back, mild hypertension, transient bradycardia and conduction block in one patient each. In conclusion, the stenotic and obliterative vascular lesions in TA can be managed successfully with angioplasty and stent placement. A long term follow up is required to determine the re-stenosis rate.

Adult subacute mountain sickness--a syndrome of congestive heart failure in man at very high altitude.

A new type of mountain sickness is described. 21 men (age 22.2, standard deviation [SD] 1.8 years) had severe congestive heart failure with oedema and ascites after 10.8 (SD 5.9) weeks at altitudes of 5800-6700 m. Investigation, within 3 days of transfer to 300 m, showed polycythaemia, cardiomegaly with right ventricular enlargement, and (in 17) pericardial effusion. The heart failure resolved rapidly after transfer from high altitude.