Vascular Responses to Post Occlusive Reactive Hyperemia and Systemic Inflammation in Overlap Syndrome of Chronic Obstructive Pulmonary Disease and Obstructive Sleep Apnea.

Background : Post-occlusive reactive hyperemia (RH) is impaired in Chronic Obstructive Pulmonary Disease (COPD) and Obstructive Sleep Apnea (OSA). The aim of the present study was to examine systemic vascular response and endothelial function in patients of Overlap Syndrome (OS) of COPD and OSA and also to investigate whether OS has any additional effect on endothelial dysfunction when compared to dysfunction caused by COPD alone. Methods : 31 COPD patients and 13 healthy controls participated in the study. Overnight Polysomnography was done to classify the patients into COPD only group (Apnea-Hypopnea Index <5) (n=15) and OS group (AHI >5) (n=16). Peripheral pulse waveform changes during reactive hyperemia were assessed using digital Photoplethysmography (PPG) technique in which pulse wave amplitude (PWA), Maximum slope of upstroke and Pulse Transit Time (PTT) were measured. C - reactive protein was assessed as marker of inflammation by ELISA. Results : Maximum percentage changes in PWA during RH were significantly lower in the both COPD group [20.34(12.02-34.07)] (p<0.001) and Overlap Syndrome group [10.96(6.21-21.49)] (p<0.0001) as compared to Controls [49.79(46.03-65.32)], whereas amplitude responses were not significantly different in the COPD and OS group (p>0.05). Maximum percentage change in slope of upstroke showed similar responses in the three groups. CRP levels (mg/l) were raised in COPD [11.60(1.75-15.00] (p<0.001) and OS group [12.52(5.28- 15.70))](p<0.0001) as compared to controls [0.59(0.58-0.91)]. Maximum percentage change in amplitude negatively correlated with serum CRP levels in COPD group (r=-0.557, p=0.03) and in OS group (r=-0.552, p= 0.02). FEV1% predicted positively correlated with maximum percentage change in amplitude in OS group

Impaired systemic vascular reactivity & raised high-sensitivity C reactive protein levels in chronic obstructive pulmonary disease.

Background & objectives: Chronic obstructive pulmonary disease (COPD) is characterized by slowly progressive airflow limitaion, chronic lung inflammation and associated systemic manifestations. The objective of this preliminary study was to investigate the levels of high sensitivity C reactive protein (hs CRP) and tumour necrosis factor-α (TNF-α) as markers of systemic inflammation and assessment of systemic vascular reactivity that may play an important role in development of cardiovascular disease in COPD patients. Methods: Systemic vascular reactivity was assessed non-invasively by measuring peripheral pulse waveform changes during reactive hyperemia (RH) in 16 COPD patients and 14 controls by photoplethysmography technique (PPG). Parameters measured were pulse wave amplitude (PWA), slope and pulse transit time (PTT). Tumour necrosis factor-α (TNF-α) and hs CRP were measured as markers of inflammation. Results: PWA during the 1st, 2nd and 3rd minutes post release of occlusion were significantly higher than the baseline means in controls, whereas in the patient group there was no significant change in the PWA during any of the observed time periods following release of occlusion, in comparison to the baseline means. Similar results were observed in slope values for patients and controls. Maximum percentage change in PWA during RH with reference to baseline was significantly lower in patients as compared to controls (26.78±20.19 vs 57.20±19.80%, P<0.001). Maximum percentage change in slope during RH with reference to baseline was significantly lower in patients as compared to controls (19.77±10.73 vs 39.25±13.49%, P<0.001). A vascular tone response as represented by PTT was also impaired in the 3rd minute of RH as compared to baseline mean values in COPD patients only. Interpretation & conclusions: Our findings showed raised hs CRP levels and impaired systemic vascular reactivity in COPD patients. Whether these may increase the risk of cardiovascular disease in COPD patients need to be confirmed in future studies with large sample size and appropriate study design.

The role of medical education unit in staff development: An experience from AIIMS, New Delhi.

Context and Setting: Attainment of health objectives depends on the capacity building of all categories of staff. While Medical Education has some provision for faculty development, the existing initiatives for staff development are too few and floating. We describe our experience in conducting a pilot training program for the administrative staff at AIIMS. Need for innovation: The competency and motivation of the administrative staff are crucial for better public dealing, and for organization’s effectiveness. In the existing system, there was no such mechanism to drive these. Description of innovation: We selected Assistants and Office Supervisors (71) for the training program. Based on brain storming meetings with administrators and keeping in view the time constraints, we identified four modules - Team building, Effective Communication, Stress management and Use of computers (Application of MS Office).Each module was of three hours duration conducted by medical faculty, educationists and management experts. All sessions were highly interactive including case scenarios, exercises, games, role play and psychometric tools. We obtained feedback from the participants to evaluate the effectiveness. Lessons learnt: An overwhelming majority (>90% participants) perceived the content and the training process as “Highly Useful” (strongest rating). The trainees found ‘Computer Application’ highly useful, because of its utility potential. ‘Communication skills’, ‘Team work’ and ‘Stress management’ were also perceived as useful for their professional and personal lives. Effective collaboration of medical faculty, educationists and management experts led to the success of this program. We recommend that such model should be a regular feature and be linked with performance appraisal.

Cardiovascular autonomic functions & cerebral autoregulation in patients with orthostatic hypotension.

Background & objectives: Patients of orthostatic hypotension may or may not have symptoms of the cerebral hypoperfusion despite fall in the blood pressure. The present study was done to quantify autonomic functions and cerebral autoregulation in patients of orthostatic hypotension with or without symptoms. Methods: The study was conducted in 15 patients of orthostatic hypotension and 15 age, sex matched control subjects. The sympathetic reactivity was measured by diastolic blood pressure response to handgrip test (ΔDBP in HGT) and cold pressor test (ΔDBP in CPT). The parasympathetic reactivity was measured by E:I ratio during deep breathing test (DBT) and Valsalva ratio (VR) during Valsalva maneuver. The cerebral autoregulation was computed from the changes in the cerebral blood flow, cerebrovascular conductance and blood pressure measured during different time points during head-up tilt (HUT). Results: The sympathetic reactivity was lower in patients as compared to controls [ΔDBP in HGT: 10 (4 - 16) vs 18 (12 - 22) mmHg, P<0.01; ΔDBP in CPT : 10 (4-12) vs 16 (10-20) mmHg, P<0.01]. The parasympathetic reactivity was also lower in patients as compared to controls. The sympathetic and parasympathetic reactivity was comparable in the symptomatic and asymptomatic patients. The maximum fall in blood pressure during HUT was comparable between symptomatic and asymptomatic patients (29.14 ± 10.94 vs 29.50 ± 6.39 mmHg), however, the percentage fall in the cerebral blood flow was significantly higher in the symptomatic (P<0.05) compared to asymptomatics. Interpretation & conclusions: Patients with orthostatic hypotension had deficits in sympathetic and parasympathetic control of cardiovascular system. Cerebral autoregulation was present in asymptomatic patients (increase in cerebrovascular conductance) during HUT while it was lost in symptomatic patients.

Acute hemodynamic effects of sildenafil in patients with idiopathic dilated cardiomyopathy.

Sildenafil, a phosphodiestrase-5 inhibitor, decreases pulmonary artery pressures (PAP) in patients with idiopathic pulmonary hypertension. There is little data pertaining to its use in unselected patients with idiopathic dilated cardiomyopathy (IDCM). A single oral dose of sildenafil (50 mg) was administered to 11 patients (mean age 44.9 +/- 7 years, 7 males) with IDCM with left ventricular ejection fraction < or = 40% in New York Heart Association class II/III at the time of right heart catheterization. There was a significant decrease in pulmonary artery systolic pressure (from 31.5 +/- 9.7 to 19.0 +/- 5.2 mmHg, p < 0.001) and pulmonary vascular resistance (PVR) (from 3.0 +/- 2.1 to 1.6 +/- 0.8 dyne/s/m(2)/cm(5), p = 0.01) following sildenafil administration. The systemic vascular resistance (SVR) and pulmonary wedge capillary pressure also significantly decreased. No significant differences in heart rate, cardiac index and PVR/SVR ratio were observed. There were no side effects documented. Sildenafil produces favorable vasodilation in both pulmonary and systemic vascular beds with decrease in left ventricular filling pressures, in stable patients with IDCM.

Autonomic status in systemic sclerosis in India.

Systemic sclerosis (SSc) is a systemic connective tissue disease characterized by vasomotor disturbances. Autonomic dysfunction has been implicated in the pathogenesis of various symptoms in patients with SSc. In this retrospective study, thirty patients with SSc as cases and thirty age matched healthy subjects were enrolled as controls. The patients as well as controls were subjected to a standard battery of autonomic tests including reactivity and activity (tone) tests. Resting autonomic variables like blood pressure (BP), heart rate (HR) and respiratory rate (RR) were also recorded. In our study, we found significantly higher HR and RR in the patient group (P = 0.0001 and 0.012 respectively). We also observed significantly lower parasympathetic tone and parasympathetic reactivity in SSc patients than the controls. This study shows the status of autonomic functions in SSc patients in India, with lower central parasympathetic drive to the heart. The present study may give some insight for better understanding of this multisystem disorder of unknown etiology.

Ocular and cardiovascular autonomic function in diabetic patients with varying severity of retinopathy.

The study was conducted to assess the ocular and cardiovascular autonomic function in diabetic patients with varying severity of diabetic retinopathy. Ocular and cardiovascular autonomic function tests were performed in 30 patients with type 2 Diabetes Mellitus (10 in each group of proliferative retinopathy, non-proliferative retinopathy and no retinopathy) of more than 5 years duration and 10 normal controls. Ocular autonomic function tests were done by measuring pupil cycle time and denervation hypersensitivity with 0.125% pilocarpine and 0.5% phenylephrine. Cardiovascular autonomic function was measured by a battery of standard tests. Denervation hypersensitivity to 0.125% pilocarpine and to 0.5% phenylephrine and pupil cycle time showed statistically significant differences (P value < 0.001) between controls and patients with proliferative retinopathy (PDR) and also between no retinopathy and PDR (P < 0.001). Systemic autonomic function tests namely expiration--inspiration ratio, difference in heart rate, 30th beat and 15th beat ratio in head up tilt and difference in diastolic blood pressure in head up tilt test also showed significant difference (P < 0.01) between controls and all 3 groups of diabetics. There was statistically significant difference found in para-sympathetic ocular autonomic dysfunction between NPDR and controls. Ocular and systemic autonomic dysfunctions are related to the severity of diabetic retinopathy.

Neurofibromatosis I with unusual hypopigmentation masquerading as leprosy.

A case of Neurofibromatosis I (NFI) occurring in association with symmetrical peripheral nerve enlargement and multiple hypopigmented macules strikingly limited to the neurofibromas, with normal to minimally reduced sensations, evoking a strong clinical suspicion of co-existent lepromatous leprosy, is being reported. Leprosy was ruled out by microbiological, histopathological and electrophysiological studies. The case is interesting in view of the hypopigmented macules overlying the neurofibromas, which is an unreported feature of NFI.

A short duration of physical training benefits cardiovascular performance.

The present study explored the possibility of short duration of supervised physical training on cardiovascular performance and attempted to look into the changes in the autonomic tone as assessed by heart rate variability (HRV), if any. The study was conducted on 25 healthy adult male subjects (mean age: 32.08+/-8.32 years) who underwent 15 days of moderate physical training on bicycle ergometer. Heart rate and blood pressure response to exercise and during recovery was monitored as well as autonomic activity (tone) was assessed by heart rate variability in resting condition and all the parameters were compared before and after physical training of 15 days. Heart rate response to graded exercise on bicycle ergometer showed a significant decrease at 2nd minute, 3rd minute, 5th minute and 6th minute during exercise after physical training, and systolic blood pressure response also showed a significant decrease at 4th minute, 5th minute and 6th minute during exercise after physical training. Physical training resulted in quick recovery during the 1st minute after cessation of exercise (percentage drop 21.03+/-7.93 vs. 23.50+/-6.97, P<0.05). Although there was no significant change in the HRV parameters, there was a trend reflecting an increase in parasympathetic tone and a decrease in sympathetic tone after physical training. We conclude from the present study that even a short duration of physical training results in favorable cardiovascular performance and it may be ascribed to autonomic modulation.

Short-term physical training alters cardiovascular autonomic response amplitude and latencies.

This study reports the results of 15 days of exercise training in 25 adult males on cardiovascular autonomic response amplitude and latencies. A standard battery of autonomic function tests including both activity (tone) and reactivity was used. Parasympathetic activity as evaluated from Heart rate variability (HRV) showed no statistically significant change in both time and frequency domain measures, similarly Sympathetic activity as measured by QT/QS2 ratio showed no statistically significant change, but there was a trend of a decrease in sympathetic activity and an increase in parasympathetic activity. There were no changes in the parameters measuring parasympathetic reactivity. Sympathetic reactivity as evaluated by diastolic blood pressure responses to hand grip test (HGT) and cold pressor test (CPT) showed significant decreases. Time domain assessment of autonomic responses was done by measuring tachycardia and bradycardia latencies during Valsalva maneuver (VM) and lying to standing test (LST). Physical training resulted in a decrease in tachycardia latency during LST and a decrease in bradycardia latency during VM. We conclude from the present study that 15 days of physical training is not enough to alter autonomic activity and PNS reactivity but can result in changes in SNS reactivity and latency parameters. We hypothesize that a decrease in bradycardia latency during VM signifies a faster recovery of heart rate during VM and a decrease in tachycardia latency during LST denotes a delayed activation of the system both of which are favorable cardiovascular responses.

Neurophysiological mechanisms of induction of meditation: a hypothetico-deductive approach.

A detailed analysis of methods of induction of meditation and meditative experience encountered therein implicates involvement of several mechanisms in inducing 'meditative effect'. 'Efferent attenuation', 'sensory attenuation' and 'cognitive restructuring' appear three possible mechanisms employed in varying degree of combinations to produce the 'meditative effect' during different types of meditations. Using hypothetico-deductive approach, it is possible to generate a neural model for explaining the 'meditative effect'. Primarily, the meditation is produced by disengaged association cortices driven by thalamus or other older group of reticular nuclei. Secondarily, there may be involvement of some more phylogenetically older structures depending upon depth and types of meditation. This model explains induction, maintenance and long-term effects of meditation.

Autonomic nervous system reactivity in irritable bowel syndrome.

BACKGROUND: Autonomic dysfunction has been implicated as one of the factors involved in the pathogenesis of irritable bowel syndrome (IBS). AIM: To evaluate autonomic function in patients with IBS. METHODS: Thirty-five patients with IBS and thirty healthy controls were evaluated by standard cardiovascular reflex tests. Parasympathetic function was assessed by measuring heart rate responses to deep and slow breathing (E:I ratio), Valsalva maneuver (Valsalva ratio) and head-up tilt tests (30:15 ratio). Sympathetic adrenergic function was assessed by measuring diastolic blood pressure responses to handgrip test at 4 min and cold pressor test at 1 min and also by change in systolic blood pressure in response to head-up tilt. Autonomic functions were tested twice, keeping at least a one-week interval, to find out stability over time. Anxiety status of the subjects was assessed by evaluating responses to a questionnaire. RESULTS: Parasympathetic reactivity was significantly increased in IBS patients as compared to controls during visit 1 (E:I 1.7 [SD 0.2] vs 1.4 [0.1], p < 0.001; Valsalva ratio 2.0 [0.3] vs 1.5 [0.1], p < 0.001; 30:15 ratio 1.2 [0.1] vs 1.1 [0.01], p < 0.001). Similar results were obtained in visit 2. The diastolic blood pressure responses during handgrip and cold pressor tests were not different in comparison to controls during both the visits. However, tilting resulted in less marked rise in diastolic blood pressure (9.1 [4.1] vs 12.1 [6.8] mmHg, p < 0.01) at 0.5 min and less rise in heart rate (6.0 [2.5] vs 10.3 [6.3] per min, p < 0.01) at 1 min in IBS patients during visit 1. The anxiety score of IBS patients was significantly higher (46.2 [3.2] vs 21.6 [1.7], p < 0.001). CONCLUSION: IBS patients have increased parasympathetic reactivity and a high level of anxiety trait.