Osman Erk

Effect of diurnal variability of heart rate on development of arrhythmia in patients with chronic obstructive pulmonary disease

We examined the possible effect of diurnal variability of heart rate on the development of arrhythmias in patients with chronic obstructive pulmonary disease (COPD). Forty-one COPD patients (M/F: 39/2, mean age: 59+/-8.5 years) and 32 (M/F: 27/5, mean age: 57+/-11 years) healthy controls were included. Twenty-four hour ECG recordings were analyzed for atrial fibrillation (AF) or ventricular premature beats (VPB), and circadian changes in heart rate variability (HRV) were assessed by dividing the 24-h period into day-time (08:00-24:00 h) and night-time (24:00-08:00 h) periods. Night-time total (TP), low frequency (LF) and high frequency (HF) powers were similarly lower from day-time parameters in AF(-) COPD patients (HF 3.91+/-1 vs. 4.43+/-1.04 ms(2), P=0.001) and controls (HF 3.95+/-0.72 vs. 4.82+/-0.66 ms(2), P<0.001). The LF/HF ratios were also significantly reduced in the same patient groups (AF(-) COPD 1.35+/-0.21 vs. 1.27+/-0.19, P=0.04, controls 1.43+/-0.14 vs. 1.24+/-0.09, P<0.001). Night-time TP and LF were increased, HF unchanged and LF/HF significantly increased (1.11+/-0.25 vs. 1.19+/-0.27, P<0.05) in AF(+) COPD patients. Frequency of VPB was correlated with corrected QT dispersion (QTc(d)) (r=0.52, P=0.001) and the day-time/night-time HF ratio (r=0.43, P=0.02). Patients with QTc(d)>or=60 ms did not have the expected increase in night-time HF and had a statistically insignificant increase in LF/HF ratio. In COPD patients with QTc(d)<60 ms, circadian changes in HRV parameters were parallel with the controls. We concluded that COPD patients with arrhythmia had circadian HRV disturbances such as unchanged night-time parasympathetic tone and disturbed sympatho-vagal balance in favor of the sympathetic system all day long, which may explain the increased frequency of arrhythmia.

Acute Wood or Coal Exposure with Carbon Monoxide Intoxication Induces Sister Chromatid Exchange

Objective: The object of this study was to investigate the genotoxic effect of acute overexposure to combustion products originating from coal or wood stoves in patients presenting with acute carbon monoxide intoxication. Study Design: In a prospective study, we analyzed the frequency of sister chromatid exchange and the carboxyhemoglobin concentration in 20 consecutive patients without a history of smoking or drug use who had been treated in the Emergency Care Unit of Istanbul Medical Faculty due to acute carbon monoxide intoxication. All of these cases were domestic accidents due to dysfunctioning coal or wood stoves. The results were compared with a control group of 20 nonsmoking, nondrug-using healthy individuals matched for age, sex, and absence of other chemical exposure. Results: The mean sister chromatid exchange frequency per metaphase was significantly higher in the study group compared to the control group: 8.11±2.39 vs. 6.33±1.60 (p=0.008). We found that there was no positive correlation between the blood carboxyhemoglobin concentration and sister chromatid exchange frequency. Conclusions: These results suggest that acute exposure to combustion products of wood or coal is genotoxic to DNA. Potential causes of genotoxicity include known mutagenic compounds present in coal or wood smoke and ash, oxygen radicals formed during combustion, as well as hypoxic and reperfusion injury mechanisms initiated by carbon monoxide intoxication. Additional studies on separate carbon monoxide exposure from smoke and ash are needed to understand individual genotoxic contributions and mechanisms.

The Effect of Air Pollution and Meteorological Parameters in Istanbul on Hospital Admissions for Acute Coronary Syndrome

It is known that air pollution and meteorological parameters have a negative effect on various respiratory and cardiovascular parameters. In this study, the relationship between emergency hospital admissions for acute coronary syndrome (ACS) and the meteorological and air pollution parameters over the same period were investigated. Some 2889 patients admitted to the emergency internal medicine unit between 1997-2001 were included in this study. The number of patient admissions per month with a diagnosis of ACS were determined and the relationship between meteorological parameters (pressure, temperature, humidity) and mean values of parameters of pollution including carbon monoxide (CO), sulphur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2), mass of particles smaller than 10 m (PM10) were investigated. Monthly admission figures for ACS were positively correlated with pressure and negatively correlated with temperature. No relationship between air humidity and admission for ACS was detected. There was also positive correlation between ACS and SO2, CO, NO and PM10levels. The results showed that the most important meteorological parameter that increased the number of admissions for ACS was a decrease in air temperature, and the most important pollution parameter was SO2. Admission for ACS significantly increased in winters and springs in comparison with summers (RR 1.15%95 CI(1.039-1.279); RR 1.16%95 CI(1.046-1.291)). Air pollution and meteorological parameters should be seen as a widespread public health problem, which can trigger admission and even death due to ACS. Greater effort should be expended to further lower air pollution levels.

Drugs with Blocking Effects on the Renin–Angiotensin–Aldosterone System Do Not Improve Endothelial Dysfunction Long-Term in Hypertensive Patients

In essential hypertension, endothelial dysfunction has been documented many times and correlates with prognosis. The influence of the renin–angiotensin–aldosterone system (RAAS) on endothelial dysfunction has also been studied. The present study investigated the duration of the effects of RAAS-blocking drugs on endothelial function in 44 consecutive, never-treated, outpatients with mild to moderate hypertension. Patients (11 per group) received an angiotensin receptor blocker (ARB; irbesartan 300 mg/day or valsartan 160 mg/day) or an angiotensin-converting enzyme inhibitor (ACEi; fosinopril 10 mg/day or quinapril 20 mg/day). If target blood pressure (< 140/90 mmHg) was not achieved, 12.5 mg/day hydrochlorothiazide was added. Endothelial function, assessed by measuring brachial artery diameter, did not change significantly after 6 weeks, 1 year or 3 years of treatment in any group. Across all groups, endothelium-dependent and-independent vasodilation increased significantly after 6 weeks but, after 1 year, decreased below baseline and was at a similar level after 3 years; groups did not differ significantly. Both ACEi and ARB had similar effects on endothelial function; improvement occurred at the start of treatment but was not maintained. Endothelial dysfunction may be a resistant or irreversible feature of hypertension, requiring high doses of antihypertensive drugs and above-average patient compliance.

FREQUENCY OF RENAL AMYLOIDOSIS SECONDARY TO TUBERCULOSIS

Osman Erk, Istanbul Universitesi, Istanbul Tip Fakültesi, Acil Dahiliye Klinigi, Çapa, Istanbul (Turkey) Dear Sir, Although tuberculosis occurs infrequently it has attracted increasing attention in recent years. In part this reflects an increased awareness of its renal complications such as amyloid deposition in the kidneys. Amyloid is often first deposited in the mesangium of the glomeruli and later extends along the basement membrane. Initially present as small focal nodules, these deposits eventually become larger, obliterate the capillary lu-mina and replace the entire tuft. Ultimately the glomeruli become atrophic and structureless and replaced by amyloid surrounded by concentric layers of collagen. Proteinuria was reported to be present in about 80% of patients and was not necessarily correlated with the extent of glomerular involvement [1]. Some investigators have noted that the severity of proteinuria correlates better with the presence of spicules and the destruction of podocytes. The greatest loss of protein probably occurs in areas where the basement membrane is disrupted by amyloid and denuded of its epithelial covering. 60% of the patients were reported to develop the nephrotic syndrome, while renal insufficiency was found in more than half of the patients at the time of diagnosis [2]. We studied the occurrence rate of tuberculosis causing renal amyloidosis. 237 patients with renal amyloidosis diagnosed by biopsies were investigated. Only 81 (35.6%) had a previous history of tuberculosis and the remaining 156 patients had amyloidosis due to other causes. Among these patients with renal amyloidosis secondary to tuberculosis, 55 (67.9%) were males and 26 (32%) were females. The mean age was 45.22 ± 3.5 years (range 21-58 years). The duration of the disease was found to vary from 1 to 6 years with an average of 2 ± 1 years. 79% of patients showed clinical manifestation of the nephrotic syndrome; only 23.4% had developed renal failure. Hepatomegaly was present in 47 (58%) and splenomegaly in 18 (22%) patients. 12 patients (14.8%) showed gastric atony, 17 patients (20.9%) emphysema and 11 patients bronchiectasis (13.5%). Pleural effusion was present in 9 cases (11.1%); 23 (28.3%) patients were hypoten-sive and 5 cases (6.1%) had peripheric neuropathy and 10 (12.3%) a fever. Laboratory findings revealed the ESR to be high in 27 (33.3%), leukocytosis in 16 (19.7%), leukopenia in 5 (6.1%), lymphocy-tosis in 3 (3.7%) and eosinophilia in 22 (27.1%) patients. In 58 (71.6%) patients the hematocrit was below 30%, and in 4 cases (4.9%) pancytopenia and in 12 (14.8%) trombocytopenia were present. In 61 patients (75.3%) αi-, c1⁄8and γ-

Autoimmune hepatitis complicated by pyomyositis

at his initial presentation, he may have been cured with a long course of antibiotics. The disease nevertheless progressed to cause small bowel obstruction and external compression of the right ureter. At this stage, the concern was that he might have either had an extensive malignant intra-abdominal tumour or inflammatory bowel disease. With the small bowel obstruction not resolving and concern about potential diagnoses, there was no other option but a laparotomy. With hindsight, a CT scan with needle guided aspiration may have suggested or confirmed the diagnosis of actinomycosis. Even at an advanced stage could he have been treated with antibiotics alone? Although the evidence to support the sole use of antibiotic therapy in advanced abdominopelvic actinomycosis is scanty, Klaaborg et al. (3) reported successful treatment in a case of widespread abdominal fistulisation to the descending colon with a 5-week course of parenteral erythromycin. Other cases of uncomplicated abdominal actinomycosis detected on endoscopy have also been successfully treated with antibiotics (9). Most authors, however, advocated a combination of surgery and long-term antibiotic treatment for complicated abdominal actinomycosis because of failure to obtain an effective bactericidal concentration of antibiotics in areas of active infection (1,6,10,11). In these reports, the preoperative diagnosis of abdominal actinomycosis had not been established, and surgery was performed for suspected abdominal malignancy or diverticulitis. To conclude that a combination of surgery and antibiotics is required without having had the opportunity to treat the condition with the sole use of antibiotics may be unjustified. Although we acknowledge that the data available are not strong enough to support the notion that antibiotic therapy will obviate the need for surgery in advanced abdominal actinomycosis, the fact that there is marked enhancement of actinomycotic inflammatory masses after administration of intravenous contrast medium suggests that there is potential for achieving adequate antibiotic concentrations in these masses (7). We suggest that initial intravenous therapy is required for larger lesions with abdominal abscesses or draining sinus tracts. The recommended dose is penicillin G 10–20 million units daily for 4–6 weeks, followed by oral penicillin (2–4 g ⁄ d) or amoxicillin for 6–12 months. For penicillin-allergic patients, tetracycline, erythromycin or clindamycin are acceptable alternatives (1,8,12).

The diagnostic value of troponin T and myoglobin levels in acute myocardial infarction: a study in Turkish patients.

This study compares the diagnostic value of troponin T (TnT) and myoglobin with creatinine kinase (CK) for myocardial infarction (MI) in a tertiary care centre in a developing nation. The study group comprised 33 acute myocardial infarction patients and 27 healthy controls. Receiver operating characteristic curves for TnT, myoglobin and CK were drawn and areas under the curve calculated. At admission, myoglobin levels had greater diagnostic sensitivity than TnT or CK levels. After 2 h, myoglobin and TnT had equal sensitivity and specificity, whereas CK still had lower sensitivity than myoglobin and TnT. After 4 h there was no difference between the tests. It was concluded that myoglobin levels on admission and TnT at 2 h had the greatest diagnostic rate, whereas all the tests were similar after 4 h for MI.