Comparison of heart rate variability in negative and positive responders to active phase of head-up tilt test

Objective: To compare heart rate variability in negative and positive responders to active phase of head-up tilt test

Study Design:Cross-sectional comparative study

Place and Duration of Study: Department of Cardiac Electrophysiology, Armed Forces Institute of Cardiology, Rawalpindi from Jan 2016 to Oct 2016

Material and Methods: Ninety three adult patients of either gender with recurrent unexplained syncope were recruited through convenience purposive sampling. The known cases of diabetes mellitus, cardiac diseases, cardiac arrhythmias and myocardial infarction were excluded from the study. Head-up tilt test was carried out on an electrically driven tilt table. DMS 300-4L Holters were used to obtain ambulatory ECG recordings during head-up tilt test. Cardio scan premier 12 lux software was used for analysis of heart rate variability frequency domain parameters

Results: Total ninety three patients of unexplained syncope were enrolled out of which, 77 [82.8 percent] patients responded positively and 16 [17.2 percent] patients gave a negative response. There was significant variation in heart rate variability frequency domain parameters being reduced in positive responders to active phase of head-up tilt test as compared to negative responders. This difference in mean values of heart rate variability frequency domain parameters between positive and negative responders was statistically significant with p-value less than 0.05

Conclusion: The heart rate variability frequency domain analysis done during initial 20 minutes of passive phase of head-up tilt test can predict the results of tests before the administration of drugs

Comparison of ventricular late potentials in patients with cardiomyopathy and healthy controls

Background: Ventricular late potentials [VLPs] are low amplitude high frequency signals present in the terminal part of QRS complex detected by signal averaged ECG. They have emerged as robust tools for arrhythmia risk stratification in patients with cardiac diseases. Early detection of ventricular late potentials in patients with cardiomyopathy can help in risk stratification of ventricular arrhythmias leading to sudden cardiac death. The purpose of this study was to compare VLPs in patients with cardiomyopathy and healthy controls

Methods: The study was conducted in Department of Cardiac Electrophysiology, Armed Forces Institute of Cardiology, Rawalpindi. Sixty patients with cardiomyopathy [any type] along with 60 healthy controls were selected through non-probability purposive sampling. Patients meeting inclusion criteria were selected for Signal-Averaged ECG [SAECG]

Results: Ventricular late potentials were seen in 14 [23.3%] out of 60 patients with cardiomyopathy, while only 5 [8.3%] out of 60 healthy controls demonstrated ventricular late potentials. There was significant variation in frequency of patients with ventricular late potentials as compared to healthy controls [p=0.02]. The mean value of fQRS was 107.53+/-37.70 in cases while 80.32+/-24.19 in controls and the difference was statistically significant [p<0.001] while insignificant for RMS and LAS [p=0.52 and 0.87 respectively]

Conclusion: The frequency of patients with cardiomyopathy having ventricular late potentials is significantly higher compared to healthy controls

Comparison of t wave alternans in patients with cardiomyopathy and healthy controls

Objective: To compare T wave alternans in patients with cardiomyopathy and healthy controls

Study Design: Cross-sectional comparative study

Place and Duration of Study: Department of Cardiac Electrophysiology, Armed Forces Institute of Cardiology Rawalpindi, from Feb 2016 to Aug 2016

Material and Methods: Sixty patients with cardiomyopathy [any type] along with sixty healthy controls of matched age and gender were recruited through non-probability purposive sampling. Patients with diabetes mellitus, cerebrovascular accident, heart failure, bundle branch block, systemic arterial hypertension and ongoing antiarrhythmic therapy were excluded from the study. DMS 300-4L Holters were used to obtain ambulatory ECG recordings. Cardio Scan premier 12 lux software was used for analysis of T wave alternans

Results: Total one twenty subjects were enrolled in the study. Cardiomyopathic patients with positive T wave alternans were 13 [21.7 %] out of 60, while only 4 [6.7%] out of 60 healthy controls demonstrated positive T wave alternans. There was significant variation in frequency of patients with positive T wave alternans as compared to healthy controls with p-value of 0.02. In cases the mean value of T wave alternans was 55.10 micro v +/- 33.58 while 39.45 micro v +/- 13.53 in controls. The difference in mean value of T wave alternans between cases and controls was significant with p-value of 0.001

Conclusion: The frequency of patients with cardiomyopathy having positive T wave alternans was significantly higher as compared to the healthy controls

Microbial spectrum of cardiac implantable electronic device infections - a tertiary cardiac center experience

The objective of the study was to determine the microbiological spectrum of cardiac implantable electronic device [CIED] infections. Case series Armed Forces Institute of Cardiology / National Institute of Heart Diseases AFIC/NIHD from January 2011 to Nov 2013. A total of 15 pus samples from patients with possible CIED infection out of 814 patients with implantable CIEDs were processed. Thirteen patients with positive cultures out of fifteen were included in the study. Clinical evidence of CIED infection included signs of inflammation and purulent drainage. A CIED infection was microbiologically confirmed based on culture yield. Blood cultures were carried out in all patients with suspected CIED infection along with trans-oesophageal echocardiography [TOE], wherever clinically indicated to exclude bacteremia and lead endocarditis. Sixty nine percent of patients with culture proven CIED infection were females and 31% were males. The mean age of patients was 61 years [range 53-70 years]. Devices included 11 PPMs, 1 ICD and 1 CRT. The most frequent organisms were gram-positive [77% of isolates]; with Coagulase-negative Staphylococci [CoNS] predominating in particular Methicillin Resistant Staphylococcus epidermidis [MRSE] in 46.4% cases followed by Methicillin Sensitive Staphylococcus epidermidis [MSSE] in 15%. Non tuberculous Mycobacterium fortuitium was isolated from pus in two patients; with PPM and ICD implants respectively. MRSA was isolated in only 01 PPM infection with evidence of lead endocarditis on TOE. Pseudomonas species was isolated from pus in one patient with CRT implant. CIED infections are more often caused by Staphylococci predominantly CoNS, although atypical Mycobacteria can be implicated

Coronary artery disease and T wave inversions in electrocardiogram at high altitude

To find out the role of coronary artery disease [CAD] as a cause of T wave inversions in electrocardiogram [ECG] in otherwise healthy soldiers who were evacuated from high altitude because of chest pain. A prospective observational study. The study was carried out at CMH Skardu from September 2003 to September 2004 fifty-four consecutive patients evacuated from height > 4000 meters [13123 feet] with symptoms of chest pain and electrocardiographic changes of T-wave inversions in a group of leads were included in the study. Echocardiography and Exercise tolerance test [ETT] was performed on all the patients. All of the patients with indeterminate or inconclusive results on ETT underwent coronary angiography at Armed Forces Institute of Cardiology, Rawalpindi. Out of 54 patients, 36 [66.7%] patients had normal exercise tolerance test. In the rest 18 [33.34%] patients coronary angiogram was done and in 04 patients it was reported abnormal. In 02 [3.70%] patients coronary angiogram confirmed coronary artery disease. In 02 patients coronary angiograms were abnormal but there was no evidence of coronary artery disease. T wave inversions at high altitude suggestive of IHD are not true indicators of underlying coronary artery disease

Hyperventilatory capacity - a predictor of altitude sickness

The aim of the study was to document link between hyperventilatory capacity and risk for developing acute mountain sickness [AMS]. This study was carried out at Karakorum Mountain ranges [Northern areas of Pakistan] from March till July 2004. 54 healthy male subjects were enrolled in this study. Arterial oxygen saturation [SpO[2]] of the subjects was measured by the pulse oximeter at rest and after 1 minute of voluntary hyperventilation at an altitude of 2833 meters. Symptoms of acute mountain sickness [AMS] were recorded on a questionnaire by using the Lake Louise consensus scoring system 24 hours after ascent to high altitude. Mean pre hyperventilation oxygen saturation [SpO[2]] was 94.07 + 0.26% whereas SpO2 after 01 minute of hyperventilation was 98.61 + 0.14% that was significantly increased [p<0.001]. The mean increase in percent oxygen saturation of hemoglobin after one minute of hyperventilation [hyperventilatory capacity] for the study group was 4.61 + 0.24% while the mean symptom score was 2.06 + 0.26. It was noted that 19 [35.2%] subjects did not develop AMS whereas 34[63.0%] subjects had mild AMS and only one subject developed moderate AMS. There was no case of severe AMS. The data reveals significant [P<0.01] association between hyperventilatory capacity and development of the symptoms of AMS [r= - 0.664]. It is evident that individuals with greater hyperventilatory capacity manifest less number of symptoms of mountain sickness. It is concluded that post hyperventilation increase in oxygen saturation at lower altitude may help to predict the susceptibility of subjects to develop high altitude sickness

High altitude illness: experience of one year

Objectives of this study was to analyze symptoms of altitude illness commonly necessitating evacuation of patients from high altitude to the base hospitals in Siachin area by simple clinical screening. This was a prospective observational. Place and duration of study was Northern areas of Pakistan. This study was carried out at altitudes of 3633 meters [GOMA] and 2833 meters [Siksa] from Oct 2003 till Oct 2004. One hundred and thirty eight patients of altitude illness were studied, who were evacuated from altitude above 4000 meters. Out of 138 cases, 103 [74.6%] patients suffered from acute mountain sickness [AMS], while 21[15.2%] patients developed high altitude pulmonary edema [HAPE] and 14 [10.1%] patients developed high altitude cerebral edema [HACE], of which 3 patients were having concomitant HAPE. The most common symptom combination was headache and vomiting which was the presenting feature in 53[38.4%] patients, followed by headache, loss of appetite and insomnia, in 41[29.7] patients. Headache was the most common single symptom present in about 120[86.96%] patients that required evacuation. The next common symptom was vomiting that was found in 51[36.96%] patients while shortness of breath was present in 33[23.91%] patients. We conclude that headache is the most common presenting symptom in all the patients of AMS. Therefore, headache at high altitude should be taken seriously, if does not respond to common medication, then patient should be evacuated to a lower altitude. The incidence of AMS, HAPE, and HACE may be reduced by improving the physical fitness of mountaineers and observing the protocol of acclimatization

Hypercholesterolemia and IHD two years experience at combined military hospital Multan

Hypercholesterolemia is a health risk, and a strong relationship between this and atherosclerosis has been established through epidemiological, experimental, and clinical trial data. We indented to reestablish this association in one of our local population. We followed 540 consecutive patients during two years period who were admitted to the medical units of combined military hospital Multan with ischemic heart disease [IHD]. Mean age of the patients was 48.39 +/- 0.61 years, mean cholesterol 214.61 +/- 1.69 mg/dl, mean high-density lipids [HDL] 50.13 +/- 1.05 mg/dl, mean low-density lipid [LDL] 154.53 +/- 2.27 mg/dl and mean triglycerides [TG] 172.81 +/- 3.63 mg/dl. Risk factors were recorded in 450 patients out of which hypertension was recorded in 120 [22.22%] patients, diabetes in 100 [18.51%] patients, family history of HID in 80[14.81%] patients while there were 150 smokers. There were 383[70.09%] male patients in whom the mean cholesterol was 213.32 +/- 2.26 mg/dl, mean LDL 151.39 +/- 2.79 mg/dl, mean HDL 49.16 +/- 1.00 mg/dl and mean triglycerides was 170.64 +/- 4.18 mg/dl. There were 157[29.10%] female patients in whom mean cholesterol was 222.94 +/- 5.07 mg/dl, mean LDL159.73 +/- 4.48 mg/dl, mean HDL 53.05 +/- 2.95 mg/dl and mean TG 178.81 +/- 8.33 mg/dl. 51[9.44%] patients [mean age 50.10 +/- 1.91] presented with acute myocardial infarction out which 43 were males and 8 females. Mean cholesterol in this group of patient was 221.36 +/- 3.70 mg/dl, mean LDL 155.17 +/- 3.28 mg/dl, mean HDL 52.09 +/- 1.22 mg/dl, mean TG 170.41 +/- 6.74 mg/dl. 22 [4.1%] patients [Mean age was 33.05 +/- 1.35] presented with unstable angina of which 13 were males and 9 females. In this group, mean cholesterol was 231.14 mg/dl, mean LDL 162.70 mg/dl, and mean HDL 42.86 mg/dl. It can be concluded from this study that hypercholesterolemia is associated with IHD and levels of cholesterol, low-density lipoproteins and triglycerides were higher than the desirable levels in our local population. Though the levels of the cardio protective HDL were also higher in our study group which was contrary to the common observation