A retrospective study of malaria infections in an intensive care unit of a general hospital in Malaysia.

AIMS: To study the clinical and demographic aspects as well as the outcomes of severe cases of malaria infections managed in the intensive care unit of the Sarawak General Hospital, Kuching from January 1996 to December 2001. METHODS: All cases of malaria admitted to the intensive care unit of the Sarawak General Hospital from January 1996 to December 2001 were identified from the intensive care records and retrospectively reviewed. RESULTS: A total of 31 cases of malaria were managed in the intensive care unit of the Sarawak General Hospital in the six-year period. Twenty-eight cases were P. falciparum infections; two were P. vivax and one was a mixed infection of P. falciparum and P. vivax. Fever with or without chills and rigors, headache, abdominal pain and vomiting were the four commonest presenting complaints for P. falciparum infections. Patients with both abdominal pain and hepatomegaly have significantly higher mortality. The fatal cases, at presentation, had higher parasite counts, higher bilirubin, aminotransferase, potassium and urea levels, but lower haemoglobin and platelet counts, and more deranged coagulation profiles compared to surviving patients. The major complications include acute renal failure, acute respiratory distress syndrome, cerebral malaria and disseminated intravascular coagulopathy, haemolytic anaemia and liver dysfunction. A single case of vivax malaria, which was complicated by septicaemic shock and disseminated intravascular coagulopathy was also documented. Higher mortality rate was documented if the antimalarial medication was not commenced on the day of admission into hospital. CONCLUSION: Several infections of P. falciparum are still associated with significant mortality. Other confounding factors include the patient's own initiating quinine therapy. Aggressive and appropriate therapy is life saving. Earlier anti-malaria treatment may improve the survival rate for falciparum malaria. The isolated case of death from P. vivax infection argues against complacency in the management of even the "benign" form of the infection.

A ten-year retrospective study of tetanus at a general hospital in Malaysia.

AIMS: To study the demographic and clinical features as well as outcomes of tetanus patients at the Sarawak General Hospital, Kuching from 1990 to 1999. METHODS: All cases of tetanus from January 1990 to September 1999 were identified from the computer record at the hospital and these were then restrospectively reviewed. RESULTS: A total of 22 cases of tetanus was seen at the Sarawak General Hospital in the ten-year period with a mean of 2.2 cases per year. There were 15 male (68.2%) and 7 female (31.8%) patients. Most cases occurred in the age group 60-69. Eighteen patients (81.8%) had a reasonably identifiable injury prior to the onset; all had their wounds debrided. Body stiffness, trismus and dysphagia were the three commonest presenting complaints. Twenty-one patients (95.5%) were admitted to the intensive care unit (ICU), with an average length of ICU stay of 21.4 days. Nineteen patients (86.4%) required mechanical ventilation for a varying period of time in the ICU. All patients (100%) had tracheostomy performed and intravenous diazepam infusion as part of their management. Twenty patients (90.9%) received intravenous crystalline penicillin as the treatment antibiotics. Twenty-one patients (95.5%) received intramuscular human antitetanus immunoglobulin. There were four deaths, accounting for a mortality of 18.2%. CONCLUSION: In general, tetanus remains in Sarawak an important disease with substantial mortality and morbidity that primarily affects unvaccinated or inadequately vaccinated individuals. It is, however, highly preventable through both routine vaccination and appropriate wound management. Our case series show comparable pattern and outcome with other case series reported in the literatures.

Corrected TIMI frame count does not predict 30-day adverse outcomes after reperfusion therapy for acute myocardial infarction.

BACKGROUND: Thrombolysis in Myocardial Infarction (TIMI) flow grading is limited by subjectivity and imprecision. The corrected TIMI frame count (cTFC) has been proposed to obviate these problems. We sought to validate the utility of the cTFC in predicting adverse clinical outcomes after reperfusion therapy. METHODS AND RESULTS: We used angiographic core laboratory data from the Intravenous nPA for Treating Infarcting Myocardium Early Study (lanoteplase versus alteplase) to assess the predictive capacity of both final TIMI flow and cTFC on 30 day-composite adverse outcome (death, reinfarction, and new or worsening congestive heart failure). Only 390 angiograms of 586 were analyzable for cTFC; 33.4% of angiograms could not be analyzed for cTFC because filling of distal landmarks was not visualized for technical reasons such as inadequate panning. The interobserver correlation for determination of the cTFC was 0.99 and the intraobserver correlation was 0.97. The cTFC in the group with adverse outcomes was 49 +/- 34; in the group without adverse outcomes, it was 44 +/- 31 (P =.27). Of note, the TIMI flow correlated with adverse outcome in the overall group of patients (P =.018, area under the receiver-operator characteristic curve [c] = 0. 590) as well as in the group of patients with cines analyzable for cTFC (P =.025, c = 0.600). The independent correlates of adverse outcomes were age (P <.001), heart rate (P =.001), TIMI flow grade (P =.027), and infarct location (P =.038) but not cTFC. CONCLUSIONS: The cTFC did not predict adverse outcomes in this population of patients but did show excellent reproducibility within our core laboratory.

Pathogenicity of attenuated infectious bronchitis viruses for oviducts of chickens exposed in ovo.

A fixed effects, completely randomized factorial design was used to study the effect of infectious bronchitis virus (IBV) inoculation at two different exposure ages and three postinoculation (PI) durations on chick oviduct pathology. Maternal antibody-positive chicken embryos at 18 days of embryonation (ED) and newly hatched chicks were inoculated with an IBV vaccine (V-IBV) or with an IBV vaccine that had been serially passaged 21 times in chick kidney tissue culture (P-IBV). Hatchability of eggs inoculated with V-IBV at 18 ED was significantly lower (27%) than eggs that were not inoculated with IBV or were inoculated with P-IBV (45-58%, P < 0.01). Chicks from all treatment groups survived to 5 days after hatch. Pathologic changes in the oviduct were evaluated at 9, 18, and 27 days PI by light microscopy. Inoculation of V-IBV and P-IBV in the presence of maternal antibodies did not result in any oviduct pathology at 9, 18, and 27 days PI. Respiratory clinical signs, however, were observed in 61% and 5% of chicks inoculated with V-IBV at 18 ED and at hatch, respectively. Respiratory clinical signs were not observed in control birds, birds inoculated with P-IBV at 18 ED, or birds inoculated with P-IBV at hatch.

Fear of flying--a Singapore perspective.

Fear of flying is a term commonly used in the Aviation Medicine community. However, heterogeneous conditions which can present with fear of flying, demand that a more stringent and systematic approach be made in one's management of the aviator with fear of flying (FOF). Cases of FOF between 1974 and 1995 presented to the Civil Aviation Medical Board and the Aeromedical Centre of the Republic of Singapore Air Force were studied for their psychopathology, psychodynamics, diagnoses, motivation for treatment, type of treatment and response to treatment, and their eventual outcome in relation of flying. 53.3% of 15 cases had Adult Situational Reaction, 26.7% had phobia of flying, 6.6% had Adjustment Disorder, 6.7% had Anxiety Depressive Disorder and 6.7% had Transient Psychosis. All cases of Adjustment Disorder were returned to flying, compared with 25% of Adult Situational Reaction, 66.7% of Phobia of Flying and none of the aircrew suffering from Transient Psychosis. Fear of flying is thus a complex phenomenon, where there is interaction of elements of mental health, neurotic roots, real and imaginary threats and life events affecting eventually the flyer's willingness to fly.

Overnight heart rate and cardiac function in patients with dual chamber pacemakers.

Animal data indicate that chronic, overnight pacing at normal evening heart rates impairs cardiac function. We examined the relationship of pacing rate and cardiac function in nine patients with dual-chamber pacemakers. We investigated two, 3-week pacing regimens (80 and 50 ppm: DDD mode) in a cross-over design. Doppler echocardiograms were performed at 1700 hours (PM) and 0600 hours (AM) at the end of each regimen. Ventricular function and preload decreased overnight (PM vs AM) with both pacing regimens. Compared to the morning values, the ratio of preejection to ejection time (PEP/ET) rose (0.43 vs 0.46), while the mean velocity of circumferential fiber shortening (Vcf) fell (1.16 cm/s vs 1.11 cm/s). Stroke volume (SV) (61 mL vs 53 mL) and ejection fraction (EF) also fell (0.56 vs 0.53) in the morning. End-diastolic volume (EDV) (94 mL vs 88 mL) decreased in the morning, as did the ratio of passive to active filling (E/A) (1.06 vs 0.96). Isovolumic relaxation time (91 ms vs 101 ms) increased overnight at both pacing rates. Systolic function decreased at 80 ppm relative to 50 ppm at both times of day. SV fell (54 mL vs 61 mL), while both EDV (92 mL vs 90 mL) end-systolic volume (ESV) increased (43 mL vs 40 mL). Contractility measured by Vcf (1.09 cm/s vs 1.18 cm/s) and PEP/ET (0.49 vs 0.41) was reduced at 80 ppm. The heart needs to rest at night by slowing its rate of contraction. Pacing at 80 ppm impairs systolic and diastolic ventricular function compared to 50 ppm. Longer term consequences of ostensibly physiological pacing rates merit inquiry, particularly in those with preexisting cardiac dysfunction.

Effects of fosinopril on exercise tolerance and clinical deterioration in patients with chronic congestive heart failure not taking digitalis. Fosinopril Heart Failure Study Group.

A total of 241 men and women with mild to moderately severe chronic heart failure (New York Heart Association functional class II [90%] or III) and a mean (+/- SD) left ventricular ejection fraction of 25 +/- 7%, entered a 24-week, prospective, double-blind, placebo-controlled trial of 10 or 20 mg/day of fosinopril, a phosphinic acid angiotensin-converting enzyme inhibitor. Patients received concomitant diuretic therapy but not digitalis. Primary end points were mean change in maximal treadmill exercise time and occurrence of prospectively defined clinical events indicative of worsening heart failure (most to least severe): death, withdrawal for worsening heart failure, hospitalization for worsening heart failure, need for supplemental diuretic or emergency room visit for worsening heart failure, and no event. At study end point, treadmill exercise time had improved in the fosinopril versus the placebo group (+28.4 vs -13.5 seconds, p = 0.047). New York Heart Association functional class had improved at end point more frequently (24% vs 13%) and deteriorated less frequently (18% vs 32%) in the fosinopril group (p = 0.003). More patients treated with fosinopril (66% vs 50%) remained free of clinical events indicative of worsening heart failure, and fosinopril-treated patients had less severe clinical events (p = 0.004). Dyspnea, fatigue, and paroxysmal nocturnal dyspnea improved more often and worsened less often in this group (p < or = 0.002), and edema showed a trend toward improvement (p = 0.088). These clinical benefits did not require concomitant digitalis therapy. Fosinopril was associated with an acceptable safety profile.

Two-dimensional echocardiographic detection of biventricular thrombi.

A 42-year-old man presented with acute myocardial infarction. The ECG on admission to hospital showed "Q wave" inferior myocardial infarction and "non-Q wave" anterior infarction. Subsequently, he was readmitted to hospital on many different occasions for cardiac failure. About 15 months after the patient was first seen, two-dimensional echocardiogram (2D echo) showed dilatation of all 4 cardiac chambers and severe global hypokinesia of the left ventricle. In addition, a large echo dense mass was seen at the apex of the left ventricle and 2 smaller echo dense masses were present at the right ventricular apex. The echocardiographic characteristics of these 3 masses strongly suggest that they represent mural thrombi. Two-dimensional echocardiographic detection of biventricular thrombi has rarely been described in the past. This case together with the previously reported case by Friedman and Buda suggest that 2D echo may be a valuable test for the diagnosis of biventricular thrombi.

Spirit possession and healing among Chinese psychiatric patients.

This is a study of the illness behaviour of 100 Chinese psychiatric patients referred consecutively to the psychiatric unit of a general hospital in Singapore. More women than men felt that their illness was due to spirit possession; but belief in possession was not related to educational status. Thirty-six patients or their relatives had consulted a traditional healer before going to the hospital. Duration of illness, sex and educational status were not associated with the tendency to seek help from the traditional healer; there was also no significant difference between psychotic or neurotic patients. The majority of depressed patients (72%) presented with somatic complaints of chest discomfort, headache and abdominal discomfort. Somatization was not related to the educational level or sex of the patients.

Role of postural status in the nocturnal hemodynamic patterns of nonhuman primates.

We compared the nocturnal hemodynamic patterns of seven tethered monkeys (Macaca mulatta) with those of seven chaired animals to determine whether the overnight changes are comparable in the two conditions. In both groups, we found a consistent hemodynamic pattern characterized by an overnight fall in cardiac output and central venous pressure and a rise in total peripheral resistance that maintained blood pressure homeostasis. The pattern of overnight change occurred despite major differences in response levels: cardiac output and central venous pressure were significantly elevated, and total peripheral resistance was significantly reduced at all times (from 1800 to 1200 h the following day) in the chaired animals relative to the tethered animals. This difference was probably due to an expanded plasma volume in the chaired animals, because stroke volume was also significantly elevated. Because the nocturnal hemodynamic pattern occurred under both conditions, it is likely that it is a stable biologic effect, which is probably related to an overnight loss in fluid volume that is not replaced in animals that sleep throughout the night.

Regional finite deformations of in situ canine pericardium.

The purpose of this study was to determine in situ regional pericardial strains over a wide range of conditions. In five open-chest, anesthetized dogs we examined deformations from biplane cineradiographs of three sets of four 1-mm diameter steel beads glued to basal, midanterior, and apical regions of the pericardium during extremes of pericardial sac sizes (inferior vena caval occlusion, baseline, and tamponade). Finite deformation theory was used to determine the planar components of the Green's strains referenced to the completely unloaded, excised pericardium at the end of each experiment. From the Green's strains the principal components, EI and EII, and the principal direction of strain were determined. The first strain invariant, I1 = EI + EII, in the basal, anterior, and apical regions during caval occlusion (1.27, 0.73, and 0.67) did not differ significantly from those in the baseline state (1.43, 0.86, and 0.76) but increased significantly (P < 0.01) during tamponade to 1.54, 1.30, and 1.08, respectively. Using end systole during inferior vena cava occlusion as a reference, the directions of principal strain in each region during each condition were aligned parallel to the spine pointing toward the tail except at the base during tamponade when there was a 70 degree rotation toward the left limb. The in situ dog pericardium is considerably strained by the underlying heart even during inferior vena cava occlusion, suggesting that a completely unloaded state cannot be achieved in situ. The regional differences in the direction but not the value of principal strain suggest that there are either regional variations in loading or material properties.

Effect of nocturnal atrial demand cardiac pacing on diurnal hemodynamic patterns.

Heart rate (HR), stroke volume (SV), intra-arterial blood pressure, and central venous pressure were recorded on a beat-to-beat basis, 18 h/day (1800-1200 h the following day), for approximately 2 mo in four monkeys (Macaca mulatta). Cardiac output, left ventricular work, and total peripheral resistance were derived from these primary measurements. During the 1st mo we measured these parameters under control conditions, and during the 2nd mo the animals were studied while HR was paced by atrial demand pacing sufficient to prevent the normal nocturnal fall in HR (approximately 10 beats/min above the fastest hourly average rate recorded during the control condition). The main hypothesis of this study was that when HR is prevented from falling, SV, which normally does not fall overnight, would fall; this hypothesis was confirmed. In addition, we observed that, during the period of pacing, relative to the control period, SV was approximately 14% greater during the early evening and 4% lower during the early morning; total peripheral resistance was similar during the early evening but was 13% higher by morning. Throughout the night, systolic pressure was approximately 4% greater, diastolic pressure was 17% higher, central venous pressure was 43% greater, and left ventricular work was 27% higher. These findings show that when HR is prevented from falling overnight by atrial demand pacing, even to a relatively modest degree, there can be very significant sustained changes in cardiovascular function.

Systematic nocturnal atrial demand pacing results in high-output heart failure.

Beat-to-beat parameters of heart rate (HR), intra-arterial blood pressure (BP), central venous pressure, and derived indexes of cardiac output and total peripheral resistance were recorded 18 h/day (from 1800 to 1200 h the following day) in four monkeys (Macaca mulatta) during 20 control days followed by 20 days of atrial demand pacing. The pacing rate was set at approximately 10 beats/min above the fastest hourly average HR recorded during the control period, i.e., sufficient to prevent the normal nocturnal fall in HR. Nocturnal pacing resulted in progressive weekly increases in central venous BP and arterial BP. Analyses of levels and diurnal trends in hemodynamic parameters and cardiac function curves across consecutive 5-day periods of nocturnal pacing revealed a hemodynamic pattern characteristic of high-output heart failure, which progressively increased (week by week) during the early morning hours (0500-0700). Sustained elevated left ventricular work resulting from the prevention of a nocturnal fall in HR may have been responsible for the reduction in cardiac function seen in this experimental model.

Coronary artery aneurysm formation following percutaneous transluminal coronary angioplasty: treatment of associated restenosis with repeat percutaneous transluminal coronary angioplasty.

Restenosis following coronary angioplasty can usually be treated effectively and safely by repeated angioplasty. However, the presence of a complex lesion morphology may bias the clinician away from angioplasty toward either recommending bypass surgery or continuing medical therapy alone in spite of recurrence of the symptoms which were sufficient indication for the initial angioplasty. One type of complex morphology at the site of the restenosis is due to the presence of a focal, eccentric aneurysmal dilatation similar in appearance to a saccular aneurysm. In two previously reported cases in the literature both were referred to bypass surgery. We report eight additional cases including the use of repeat successful angioplasty in six of the cases in spite of the potential problems posed by the complexity of the restenosed lesion. In addition, this case review suggests that this type of complex lesion morphology with restenosis may be more common when the initial angioplasty was associated with deep arterial injury, as in patients whose initial angioplasty was done in an infarct-related vessel or was associated with evidence of a large dissection.

Oversensing from electrode 'chatter' in a bipolar pacing lead: a case report.

An 81-year-old man was treated for high degree AV block and syncope with an AV universal (DDD) pacemaker. Bipolar active fixation atrial and ventricular leads were used. Intermittent oversensing from the ventricular lead was detected on Holter monitoring following implantation. This resulted in inappropriate inhibition of ventricular pacing. Ventricular electrogram showed spurious signals between 5 mV and 15 mV in magnitude coincident with ventricular lead inhibition. Treatment consisted of reprogramming the device to the VVT mode. Six weeks after implantation normal pacemaker function in the DDD mode was demonstrated on Holter monitoring and inappropriate pacer inhibition could not be demonstrated. We postulate that electrode 'chatter' between the cathodal ring electrode and the helix of the ventricular lead resulted in artifactual potentials sufficient to inhibit pacing. We hypothesize that fibrosis and fixation of the ventricular lead tip over a period of weeks eliminated these electromechanical artifacts and resulted in the oversensing problem being self-limited. Physicians should be aware of electrode 'chatter' as a cause of pacemaker oversensing.

Transverse stiffness: a method for estimation of myocardial wall stress.

Determination of regional ventricular wall stress would allow quantification of both regional contractile state and its interplay with global function. Current methods for quantifying regional stress include mathematical modelling and measurements with strain gauges. Both methods are difficult to validate. We hypothesized that transverse stiffness (i.e., the ratio of indentation stress to strain as the ventricular wall is indented in the direction perpendicular to the wall) would be proportional to the stresses in the plane of the wall and could be used to estimate the latter. To test this hypothesis, 6 arterially perfused canine ventricular septa were mounted in an apparatus that could exert biaxial load in the plane of the wall. A servo system maintained the central third of the septa isometric during active contractions while the septa were paced at 30-60 pulses/min. In the center of the isometric region, a probe of 7 mm diameter indented the septa while the transverse indentation stress and strain were measured. For values of peak systolic in-plane stress from 0.56 to 2.6 g/mm2, the transverse stiffness varied from 1.2 to 11.7 g/mm2 and was linearly related to the in-plane wall stress in each septum (p less than 0.001, ANOVA). After cardioplegia, the transverse stiffness also correlated with passively applied wall stress for each dog (p less than 0.001). The slopes of the individual relations between transverse stiffness and wall stress from active contractions were similar to those from passively applied stress (mean +/- SEM; 1.82 +/- 0.36 versus 1.45 +/- 0.31, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

An angiographic and functional comparison of patients with silent and symptomatic treadmill ischemia early after myocardial infarction.

Sixty consecutive patients were studied who had positive responses to Naughton exercise treadmill testing (at least 1.5 mm of ST-segment shift in at least 2 leads or thallium reperfusion abnormalities) with or without symptoms of angina 11 +/- 1 days after acute myocardial infarction (AMI). All patients had undergone coronary angiography 24 +/- 4 days after infarction. Thirty-eight patients (63%) had no treadmill angina (silent ischemia, group I) and 22 patients had typical treadmill angina (symptomatic ischemia, group II). Use of beta-blocking drugs, calcium antagonists and nitrates at the time of exercise testing did not differ in the 2 groups. All 9 patients with diabetes mellitus were in the asymptomatic group (p less than 0.40) and group I had a greater proportion of inferior wall AMI (30 of 38) than group II (11 of 22, p = 0.02). Total exercise treadmill test duration (group I 422 +/- 31 seconds, group II 400 +/- 46 seconds) and rate-pressure product were not different in the 2 groups. The number of patients unable to exercise 5 minutes (12 in group I and 7 in group II), the number with diffuse electrocardiographic changes (9 in group I and 7 in group II), and the number with inadequate blood pressure response (8 in group I and 4 in group II) were also similar. At coronary arteriography the mean number of arteries with at least 70% diameter stenosis was 2.0 +/- 0.2 in group I and 2.2 +/- 0.2 in group II (difference not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification of the mechanical properties of noncontracting canine myocardium under simultaneous biaxial loading.

Detailed understanding of cardiac mechanics depends upon accurate and complete characterization of the three-dimensional properties of both normal and diseased myocardial tissue. This, however, can only be obtained by performing multiaxial tests on cardiac tissue. In this study we subjected thin sheets of passive canine left ventricular myocardium to various combinations of simultaneous biaxial stretching. During each stretch the ratio of the orthogonal strains was kept constant and the corresponding stresses remained proportional. We fitted the biaxial stress-strain data both with exponential strain-energy functions with quadratic powers of strains as well as with an alternative function with nonintegral powers of strains. We used our recently developed nonparametric method to assess the reliability of the coefficients for each of these functions. The quadratic strain-energy functions resulted in wide intra- and interspecimen variability in the coefficients. Moreover, both their absolute and relative values demonstrated marked load history dependence such that interpretation of the direction of anisotropy was difficult. Fitting the data with the alternative nonintegral strain-energy function seemed to alleviate these problems. This alternative strain-energy function may provide more self-consistent results than the more commonly used quadratic strain-energy functions.

Biaxial stress-strain properties of canine pericardium.

Interpretation of the material properties of biological tissues under biaxial loading conditions has been hampered by wide variability in the coefficients. This variability has been attributed to experimental noise, numerical instability of the fitting algorithms, or to history dependence of the tissue. We have recently described quantitative methods for addressing some of these difficulties in interpretation. This study describes the application of these methods to anterior sheets of mongrel canine pericardium studied in vitro. Each specimen was stretched biaxially with three different combinations of strains and the resulting stress-strain relationships were fitted with a 5-parameter pseudo strain-energy function. Results show that each specimen is highly nonlinear, anisotropic, and history dependent. In addition there was wide inter-specimen variability in the material coefficients. In some cases the direction of the anisotropy was also history dependent. Possible explanations for this unexpected behaviour are discussed.