Aspergillus colonization in patients with chronic obstructive pulmonary disease

Background and Purpose:

Chronic obstructive pulmonary disease (COPD) has been recognized as a risk factor for invasive aspergillosis. Airway colonization by Aspergillus species is a common feature of chronic pulmonary diseases. Nowadays, the incidence of COPD has increased in critically ill patients. The aim of the present study was to isolate and identify Aspergillus colonies in the respiratory tract of COPD patients.

Materials and Methods:

This study was performed on 50 COPD patients, who were aged above 18 years, and were in intensive care units of three hospitals in Sari, Iran, for at least six days. All the samples obtained from sputum, bronchoalveolar lavage, and tracheal aspirates were cultured for fungi each week. According to the conventional techniques, Aspergillus isolates were initially based on growth and standard morphological characteristics. To confirm the identification of grown Aspergillus, the partial beta-tubulin gene was sequenced using specific primers.

Results:

A total of 50 patients, who met our inclusion criteria, were enrolled in the study during 2012-14. The results showed that 27 (54%) and 23 (46%) of the participants were male and female, respectively. The majority of the patients developed dyspnea followed by hemoptysis, chest pain, and high fever. Corticosteroids and broad-spectrum antibacterial agents were administered to 75% and 80% of the patients, respectively. Based on the conventional and molecular approaches, A. fumigatus (seven cases; 43.7%), A. flavus (five cases; 31.2%), A. niger (one case; 6.2%), A. terreus (one case; 6.2%), A. orezea (one case; 6.2%), and A. tubingensis (one case; 6.2%) were recovered.

Conclusion:

Recovery of Aspergillus species from the respiratory tract of COPD patients with pneumonia indicates two possibilities: either colonization or invasive aspergillosis.

Frontal sinus mucopyelocele with intracranial and intraorbital extension

This case is related to a 52-year-old lady with proptosis, diplopia and diminution of vision due to a mass lesion in upper medial quadrant of the orbit. CT scan revealed a well defined mass in basi-frontal area with intra-orbital and intracranial extension. On exploring it was found to be mucopyocele of the frontal sinus. Surgical excision was done by external approach. The symptoms and signs resolved completely within a week. Frontal sinus mucopyoceles are benign and curable. Early recognition and management of them is of paramount importance because they can expand and cause local, orbital or intracranial complications.

Vector ecology and susceptibility in a malaria-endemic focus in southern Islamic Republic of Iran

This study aimed to carry out a malaria situation analysis, species composition and susceptibility levels of the main malaria vector, Anopheles stephensi, to different insecticides in Bashagard. A longitudinal survey was conducted in 2 randomly selected villages in Bashagard. Malaria vectors were sampled by dipping method for the larvae and hand catch, night-biting catch, total catch, and shelter pit collection for the adults. Standard WHO susceptibility tests were used for a variety of insecticides on F1 progeny of An. stephensi reared from wild-caught females. In total, 693 adult anopheline mosquitoes and 839 third and fourth-instar larvae were collected and identified. They comprised 7 species; the most abundant adult and larvae anopheline mosquito was An. dthali (40.7% and 30.5% respectively). An. culicifacies (24.2%) and An. stephensi (16.7%) were the next most common species for adult mosquitoes. An. stephensi was fully susceptible to malathion and pyrethroid insecticides but resistant to DDT and tolerant to dieldrin.

Entomological and epidemiological attributes for malaria transmission and implementation of vector control in southern Iran

Bashagard is an important malaria endemic area in south of Iran. An epidemiological and entomological survey was performed during 2002-2010. The aim of study was to determine malaria situation, species composition of anopheline mosquitoes and susceptibility status of main vectors to insecticides/larvicides. A total of 13,490 malaria cases were recorded, Plasmodium vivax (99.64%), P. falciparum (0.35%) and mix cases (0.01%). The highest and lowest Annual Parasite Incidence (API) were observed in 2007 (145.72/1000) and 2009 (6.29/1000), respectively. Anopheles culicifacies, An. dthali, An. stephensi, An. superpictus, An. fluviatilis, An. moghulensis, An. turkhudi and An. apoci were collected from the area. Two peak activities occur in April and October. The first five species were confirmed as malaria vectors in Iran. No indication of sporozoite in mosquitoes using molecular method was performed. Susceptibility tests using diagnostic dose of insecticides and larvicides showed only resistance of An. stephensi to DDT. Tolerance in An. stephensi to deltamethrin and bendiocarb is reported. The same phenomenon was observed in An. culicifacies to DDT, propoxur and deltamethrin, and in An. dthali to malathion and deltamethrin. Larvae of vectors were susceptible to all larvicides, except for An. stephensi that exhibited tolerance to fenthion. In conclusion it should be emphasized that malaria transmission is a complex process in Bashagard. This event is attributed to five proven vectors with different behaviors which are active in the area. Regarding tolerance of vectors to deltamethrin, resistance management is suggested by using new insecticide with novel mode of action.

The Occurrence of Red-Back Spider Latrodectus hasselti (Araneae: Theridiidae) in Bandar Abbas, Southern Part of Iran

BACKGROUND

Due to importance and fatal affect of Red-back spiders, Latrodectus hasselti, a faunistic survey for presence of this spider in Bandar Abbas has been conducted. This animal is considerably the most medically importance spiders all over the world.

METHODS

Live adult spider specimens were collected from Bandar Abbas town using hand catch conventional method and transferred to the laboratory throughout the summer of 2008. They were identified based on morphological characteristics and taxonomic keys and confirmed by some external experts.

RESULTS

Results showed the occurrence of the red-back spider, L. hasselti from Bandar Abbas, southern port of Iran. Two female specimens were found. The spider had specific morphological characters including black color with an obvious orange to red longitudinal strip on its upper parts of abdomen.

CONCLUSION

Although the specimens were collected from south of the country, however since the region is an important harbor and port and goods come form different parts of world we assume the possibility of arrival from its origin and native breeding sites of the world. Therefore further investigation is needed to clarify the presence of this species in different parts of Iran.

Bionomics of Anopheles stephensi Liston in the malarious area of Hormozgan province, southern Iran, 2002

Anopheles stephensi Liston is an important malaria vector in Hormozgan province, where it is the most prevalent anopheline mosquito. It shows two annual activity peaks, one in spring and another in the autumn. In mountainous areas the second peak starts earlier than in coastal regions. Adults are endophilic and endophagic, but in the hot season when people sleep outside buildings they frequently bite outdoors. Larvae are found in a wide-range of habitats, both natural and man-made. All three biological forms of the species, occur in the province, i.e. An. stephensi stephensi (type form), An. stephensi mysorensis, and the intermediate form. An. stephensi mysorensis is found only in rural-mountainous areas, whereas the type and intermediate forms occur in urban-coastal regions and the rural plains, with the type form predominant. The presence of the type form in urban areas and mysorensis in rural areas is consistent with the available epidemiological data for malaria in the region and with the finding in India that the type form is an efficient malaria vector inhabiting urban areas whereas mysorensis is rural and has a lower vectorial capacity. Insecticide susceptibility tests on field collected adult mysorensis and adults from laboratory strains of the type and intermediate forms were carried out according to WHO standard methods. These showed that all three forms are susceptible to bendiocarb, propoxur, malathion, fenitrothion, deltamethrin, permethrin, cyfluthrin, and lambdacyhalothrin, but are resistant to DDT and show low level of tolerance to dieldrin. Examination of the larvicidal activity of malathion, fenitrothion, temephos and chlorpyrifos at diagnostic doses showed that these stephensi forms are susceptible to all larvicides except fenitrothion. Irritability tests to pyrethroid insecticides showed high levels of irritability to permethrin and lambdacyhalothrin, but low irritability to cyfluthrin and deltamethrin. The importance of these findings for the epidemiology and control of malaria in the region are discussed.

ELECTIVE EXPERIENCES OF FOREIGN MEDICAL STUDENTS AT THE TEACHING HOSPITAL OF TRIBHUVAN UNIVERSITY INSTITUTE OF MEDICINE, NEPAL

This paper has attempted to document and analyze the trend and experiences of foreignmedical students enrolled in the elective programme organized by the MedicalEducation Department (MED) at the Teaching Hospital of the Tribhuvan University(TUTH), Institute of Medicine in Kathmandu. Elective documents have been analyzedfor the period between 1997-2000 and a written questionnaire survey has beenadministered to a total of 73 foreign medical students who completed elective in theyear 2000. Over a period of four years a total of 268 students had undergone electiveposting in various departments of TUTH. More than half of the students (55%) camefrom European universities. More than 60% of respondents (n=73) considered theopportunity to see variety of patients as the main strength of the elective programme.Overwhelming majority of respondents (95%) rated the learning experience as goodor excellent. The most favoured department was the Internal Medicine. The studydemonstrates the unique value of elective in enriching student learning in medicaleducation. The traditional belief that all students should have a uniform curriculumthroughout their training has been largely challenged.1The insights gained couldperhaps, inspire medical schools to seriously think about introducing elective provisionas an essential component of their undergraduate curricula.1. Medical Education Department, TU Institute of Medicine.Address for correspondence : Dr. D. S. Pant, MD, MHPED,Assistant Director & Elective Programme Coordinator,Medical Education Department, TU Institute of Medicine,P.O. Box: 1524, Kathmandu, Nepal.Email: dspant@healthnet.org.np, Home Page: www.nchped.org.npKey Words: Elective terms, overseas elective, elective experience in developingcountries, core and elective options, undergraduate medical elective.

A rapid troponin-I-based protocol for assessing acute chest pain

In a prospective randomized open trial with 30-day follow-up, we compared a troponin-I-based protocol to 'standard management' for the diagnosis and risk stratification of patients with acute non-ST-elevation chest pain. Patients with acute chest pain (n=400) were randomized to standard diagnostic tests and management, or a protocol based on the admission ECG and the troponin-I result 6 h after onset of chest pain. Low-risk patients were discharged early from CCU; high-risk patients were treated with medical therapy or referred for in-patient angiography as appropriate. We measured length of CCU stay, and followed all patients for major adverse cardiac events (MACE) of death, non-fatal myocardial infarction (MI), or urgent revascularization during the admission and for 30 days post-discharge. The troponin protocol allowed earlier discharge in the low-risk group (10 vs. 30 h, p<0.001) with no excess of adverse events compared to standard management (3% vs. 5%, p=0.32). It identified a group of patients at moderate risk of cardiac events (15% MACE rate during admission and 30-day follow-up), and a high-risk group (75% MACE rate) more accurately than did standard management. The prognostic power of troponin testing in combination with the admission ECG was higher than with either test used alone. The protocol improved the efficiency of low-risk patient management, and improved patient risk stratification. This study adds to the evidence favouring troponin evaluation as part of the management of acute coronary syndromes.

Improvement in midwall myocardial shortening with regression of left ventricular hypertrophy

Despite normal indices of left ventricular (LV) chamber function, patients with LV hypertrophy (LVH) due to hypertension are thought to have depressed midwall systolic shortening compared with normotensives. The aims of the present study were (1) to confirm this observation and (2) to assess the effects of antihypertensive therapy that cause regression of LVH on LV systolic function assessed at both the midwall and endocardium. Thirty-eight previously untreated hypertensive subjects with LVH underwent echocardiography and were compared with 38 normotensive control subjects. Comparisons between the group with LVH and the control group revealed no significant differences in cardiac output (4. 32+/-0.23 versus 4.55+/-0.21 L/min), ejection fraction (62.5+/-2% versus 66.4+/-1.07%), or endocardial fractional shortening (34.5+/-1.45% versus 37.0+/-0.82%), but shortening assessed at the midwall was significantly less in the group with LVH (17.9+/-1.11% versus 21.6+/-0.63%, P<0.01). Subsequently, 32 patients with uncontrolled hypertension (24 previously untreated and 8 on existing antihypertensive therapy) underwent treatment with ramipril, with the addition of felodipine and bendrofluazide if required, to reduce blood pressure to <140/90 mm Hg. These 32 patients underwent echocardiography at baseline, after blood pressure control, and after an additional 6 months of tight blood pressure control. Good blood pressure control was achieved after 6 months compared with baseline (143/86+/-2.8/1.4 versus 174/103+/-4.1/1.9 mm Hg; P<0.01) with significant regression of LV mass index (124+/-3.4 versus 145+/-3.8 g/m(2), P<0.01). LV fractional shortening assessed at the midwall improved with regression of LVH (21.9+/-0.84 and 18.7+/-1. 19%, P<0.05), with posttreatment midwall shortening being similar to that of the normal control subjects evaluated in the first study. Hypertensive patients with LVH have depressed midwall systolic shortening despite normal indices of LV chamber function. Regression of LVH after good blood pressure control improved midwall shortening to normal levels.

Randomised comparison of antero-lateral versus antero-posterior paddle positions for DC cardioversion of persistent atrial fibrillation

We designed a prospective, randomised, single-blind trial to compare the relative efficacy of antero-lateral versus antero-posterior paddle positions for DC cardioversion of persistent atrial fibrillation. A total of 59 patients were randomised to cardioversion using standard gel pads placed either in the antero-lateral (AL) or antero-posterior (AP) positions. The first synchronised shock was given at 360 J; if this was unsuccessful, a second shock of 360 J was given in the alternative position. We compared cardioversion success rate and energy requirements with each strategy. With the first 360 J DC shock, a significantly greater proportion of patients were restored to sinus rhythm from the antero-lateral position (18/30) compared to the antero-posterior position (10/29) (P=0.048). For those patients remaining in atrial fibrillation, there was no difference in the proportions cardioverted from the antero-lateral position (4/19) compared to the antero-posterior position (5/12) with the second 360 J DC shock (P=0. 22). The total cardioversion success rate was 23/30 (77%) for antero-lateral followed by antero-posterior shocks compared to a success rate of 14/29 (48%) for antero-posterior followed by antero-lateral shocks, and this difference was significant (P=0.024). There was no significant difference in the mean energy delivered for patients randomised to an initial antero-lateral shock (504 J), compared to patients given an initial antero-posterior shock (583 J) (P=0.1). We conclude that the antero-lateral paddle position appears more effective for DC cardioversion of persistent atrial fibrillation.

Randomised double blind trial of oral versus intravenous flecainide for the cardioversion of acute atrial fibrillation

OBJECTIVE

To investigate whether an oral loading dose of flecainide is as safe and effective as intravenous flecainide for the cardioversion of acute atrial fibrillation.

DESIGN

Prospective, randomised, double blind, double placebo study.

SETTING

Cardiac care unit of a large district general hospital in the UK.

PATIENTS AND METHODS

79 patients presenting with symptomatic acute atrial fibrillation: patients were given either intravenous flecainide (n = 39) or a solution of oral flecainide (n = 40), with appropriate placebos. All patients were heparinised during the study.

PRIMARY OUTCOME MEASURES

Safety; mean time to cardioversion; proportion of patients restored to sinus rhythm at two hours and eight hours after treatment. Analysis was by intention to treat.

RESULTS

There were no differences in baseline characteristics between the oral and intravenous groups. Both forms of flecainide were well tolerated, with no adverse clinical events during the study. The mean time to cardioversion was 110 minutes in the oral group and 52 minutes in the intravenous group (p = 0.002). Two hours after treatment, 27 of the 40 patients in the oral group (68%) and 25 of the 39 in the intravenous group (64%) had reverted to sinus rhythm (p = 0.74). Eight hours after treatment, 30 patients in the oral group (75%) and 28 in the intravenous group (72%) had reverted to sinus rhythm (p = 0.76).

CONCLUSIONS

Intravenous flecainide restored sinus rhythm more rapidly than oral flecainide, but at two hours and eight hours after treatment there was no difference in the proportion of patients cardioverted by the two approaches. These results suggest a role for oral loading doses of flecainide in the treatment of acute or symptomatic paroxysmal atrial fibrillation.

Absence of sympathetic overactivity in Afro-Caribbean hypertensive subjects studied by heart rate variability

Black hypertensives present a greater prevalence of left ventricular hypertrophy and an increased mortality compared to white hypertensives. Differences in sympathetic activity might contribute to explain these racial differences in hypertension. Nevertheless, previous laboratory studies did not show any increase of sympathetic activity direct to the heart in black subjects. The aim of the present study was to investigate the cardiac sympatho-vagal balance in black and white hypertensives analysing heart rate variability, during the entire 24 h. We analysed Holter recordings of 52 essential hypertensive patients, who had never received antihypertensive treatment, 26 of whom were black and 26 were white. Consecutive series of 300 beats, with 150 beats overlapped (approximately 600 series/day), were considered for the analysis in time and frequency domain. The mean 24-h value of the power of the low frequency spectral component (0.04-0.15 Hz), expressed in normalised units, ie a marker of sympathetic modulation, was significantly lower in the group of black patients compared to whites (respectively 40.0 +/- 2.1 vs 53.6 +/- 3.6 nu, P < 0.01). Similar results were observed for the LF/HF ratio, an index of the sympatho-vagal balance (respectively 4.11 +/- 0.58 vs 5.98 +/- 0.79; P < 0.05). In a multiple linear regression analysis, considering diastolic blood pressure, left ventricular mass index, race and age as independent variables, only race (P < 0.002) and age (P < 0.01) could independently predict the normalised low frequency power or the LF/HF ratio, as dependent variables. The results of this study suggest some blunting of the cardiac sympathetic neural modulation in black hypertensives compared to white hypertensives, during the entire 24 h.

QT dispersion in athletic left ventricular hypertrophy

OBJECTIVE

To assess whether physiologic left ventricular hypertrophy as a result of physical training is associated with an increased QT length or dispersion.

METHODS

Thirty-three subjects were assessed. These consisted of a group of international endurance athletes (including 8 rowers, 2 cyclists, and 1 triathlete), a group of 12 professional soccer players, and a further group of 10 control subjects. Each underwent 2-dimensional echocardiography and 12-lead electrocardiographic examination.

RESULTS

Left ventricular mass index was considerably greater in both the endurance athlete (163.3 +/- 14.4 g/m2; P <.01) and soccer player groups (144.2 +/- 5.5 g/m 2; P <.05) compared with the controls (109.2 +/- 6.3 g/m2). In spite of these large differences in cardiac structure there were no significant differences in QT parameters between the groups (QT dispersion 56.9 +/- 5.5, 68.5 +/- 9.5, and 67.2 +/- 12.6 ms; QTc dispersion 61.4 +/- 9.2, 69.4 +/- 13.3, and 54.2 +/- 6.5 ms; maximum QT 402 +/- 10.3, 404 +/- 9.6, and 392 +/- 14.0 ms; and maximum QTc 404 +/- 7.0, 413 +/- 9.3, and 399 +/- 9.9 ms among endurance athletes, soccer players, and controls, respectively).

CONCLUSION

Left ventricular hypertrophy occurring as a consequence of athletic training does not appear to be associated with a major increase in QT length or QT dispersion.

Influence of sub valvular pathology on immediate results and follow up events of Inoue balloon mitral valvotomy

We evaluated the influence of sub valvular pathology (SVP) on the immediate results and follow up events of Inoue Balloon Mitral Valvotomy (IBMY) in 206 patients with severe SVP (Group I) and compared their outcome with 206 age and sex matched patients selected from the rest of 619 patients having mild/moderate SVP (Group II). Pre-procedure echocardiographic recordings were reviewed and mitral valve morphology was evaluated using U.S. California Score. The severe SVP group had lower mitral valve areas (MVA) (0.7 cm2 vs. 0.8 cm2) and higher mean pulmonary artery pressure (MPAP) (46.3+/-16.9 mmHg vs. 40.7+/-16.25 mmHg) and mean pulmonary capillary wedge pressure (PCWP) (27.5+/-7.3 mmHg vs. 25.7+/-8.0 mmHg) (p<0.001). IBMV was done using standard technique. The procedure was technically successful in 192/206 patients (93.2%) in group I and 187/206 (91%) in group II (p=ns). The mean transmitral gradient decreased from 24.8+/-7.6 mmHg to 7.46+/-3.4 mmHg while mean PCWP fell from 27.5+/-7.3 mmHg to 12.2+/-5.6 mmHg and MPAP fell from 46.3+/-16.9 mmHg to 23.6+/-12.2 mmHg (p=<0.001). MVA increased from 0.7+/-0.2 cm2 to 1.7+/-0.4 cm2 (p=<0.001). Severe mitral regurgitation (MR) occurred in 2 patients out of which one patient, who had associated coronary artery disease, died post operatively, and moderate MR occurred in 8 patients. The results achieved in patients with severe SVP were not statistically different from those with mild/moderate SVP. The benefits achieved immediate post IBMV were sustained in 184 patients with severe SVP who were available for follow up at a mean duration of 15.2 months (range 3 months to 51 months). Thus IBMV is safe and effective in patients with severe SVP. This group of patients with severe SVP are more hemodynamically deranged pre-BMV and also achieve better hemodynamic benefit compared to those with mild/moderate SVP. Severe SVP does not have any adverse effect either on immediate results (success/occurrence of MR) or on intermediate term follow up.

The effect of reduction of door-to-needle times on the administration of thrombolytic therapy for acute myocardial infarction

Optimal management of acute myocardial infarction requires rapid administration of thrombolytic therapy. However, only patients who fulfill the following specific criteria are likely to benefit from this treatment: admission within 12 hours of the onset of symptoms, no contraindications, ST elevation or possible new-onset left bundle branch block on the admission electrocardiogram. We employed an aggressive policy to reduce the delay between admission to hospital and the administration of thrombolysis (the 'door-to-needle time'), and investigated whether this approach affected the accuracy of administration of thrombolysis. Patients admitted to the cardiac care unit with acute myocardial infarction, or who were thrombolysed, were identified retrospectively over two equivalent 4-month periods before and after implementation of our policy. Patients were considered eligible for thrombolysis if they fulfilled the criteria mentioned above. The mean (SD) door-to-needle time for all patients who received thrombolysis on admission decreased from 61(70) to 19(20) minutes (p = 0.0004). The proportion of patients eligible for thrombolysis who received treatment increased from 24/38 to 30/30 (p = 0.0002). However, the proportion of patients receiving thrombolysis who did not fulfill our criteria also increased, from 3/27 to 11/41 (p = 0.1). There were no complications of thrombolysis in the first study period, but two cerebrovascular accidents in the second period; both patients fulfiled our criteria for treatment. We conclude that simple educational measures greatly reduced door-to-needle times and led to a higher proportion of eligible patients receiving thrombolysis. However, greater pressure on medical staff to make rapid management decisions increased the proportion of patients being thrombolysed inappropriately.

Ethnic differences in the hypertensive heart and 24-hour blood pressure profile

Black hypertensive persons have been observed to have a greater degree of left ventricular hypertrophy than white hypertensives. However, previous studies have matched groups for blood pressure (BP) measured in the clinic, and it has been demonstrated that black hypertensives have an attenuated nocturnal BP dip. Clinic BPs may thus underestimate mean 24-hour BP in this group. To investigate whether the differences in left ventricular hypertrophy can be accounted for by the greater mean 24-hour BP in black hypertensives, 92 previously untreated hypertensives were studied with 24-hour ambulatory BP monitoring and echocardiography. The 46 black hypertensives (24 men and 22 women) were matched with the 46 white hypertensives for age, gender, and mean 24-hour BP. Despite similar mean 24-hour BPs (blacks, 142/93 mm Hg; whites, 145/92 mm Hg; P=.53/.66), the black group had a smaller mean nocturnal dip than the white group (blacks, 8/8 mm Hg; whites, 16/13 mm Hg; P<.01). In addition, mean left ventricular mass index (LVMI) was greater (blacks, 130 g/m2; whites, 107 g/m2; P<.001). Mean 24-hour systolic BP was significantly related to LVMI in both groups (blacks, r=.45, P<.01; whites, r=.56, P<.01). However, systolic BP dip correlated inversely with LVMI only in the black group (blacks, r=-.30, P<.04; whites, r=.05, P=.76). In a multiple regression model, LVMI was independently related to both mean daytime BP and mean nocturnal BP dip in black subjects but only to mean daytime BP in white subjects. In conclusion, the increased left ventricular hypertrophy observed in black hypertensives compared with white hypertensives is not accounted for by differences in mean 24-hour BP. However, LVMI in black hypertensives appears to be more dependent on nocturnal BP than that in white hypertensives; this, coupled with the attenuated BP dip in black hypertensives, suggests that the BP profile rather than 24-hour BP may be important in determining the differences in left ventricular hypertrophy.

Immediate and follow up results of Inoue balloon mitral valvotomy in juvenile rheumatic mitral stenosis

BACKGROUND AND AIMS OF THE STUDY

Juvenile rheumatic mitral stenosis (MS) with severe pulmonary venous and arterial hypertension (PAH) is a relatively common occurrence in developing countries. The study objectives were to evaluate the safety, efficacy and follow up of Inoue balloon mitral valvotomy (IBMV) in juveniles with rheumatic MS.

METHODS

A total of 193 patients with juvenile rheumatic MS were analyzed and compared with adults, with specific reference to the effect of IBMV on hemodynamics and pulmonary vasculature in patients with severe PAH.

RESULTS

Mitral valve areas were smaller (0.76 +/- 0.22 versus 0.81 +/- 0.22 cm2), while mean pulmonary arterial pressure (MPAP) (44.5 +/- 16.5 versus 38.4 +/- 15.1 mmHg) and pulmonary vascular resistance (PVR) (5.5 +/- 4.6 versus 4.41 +/- 4.04 Wood units) were greater in juvenile patients when compared with adults. There was a 99% procedural success. Juvenile patients showed an overall greater fall in MPAP and PVR when compared with adults. The incidence of severe PAH was much higher (32%) among juveniles than adults (16%). Only 5% of patients with juvenile MS with severe PAH had residual severe PAH immediately after IBMV, compared with 17% in older patients. Hemodynamic benefits (echocardiographic mean transvalvular gradient and mitral valve area) were sustained at a mean follow up of 29 months, and there was no documented case of restenosis after successful IBMV.

CONCLUSIONS

We conclude that IBMV is safe and effective in juvenile rheumatic MS and provides greater hemodynamic benefit compared with adults; such benefit is sustained during a mean follow up of 29 months.

Left ventricular geometry in presenting untreated hypertension

In order to investigate the spectrum of geometry in our patient population, 63 untreated hypertensives underwent two-dimensional echocardiography. Left ventricular (LV) mass index and relative wall thickness, a measure of wall thickness in relation to cavity size, were calculated from the M-mode strip. In addition, to assess the sphericity of the left ventricle the ratio of LV minor to major hemiaxis was calculated. The subjects comprised 41 men (17 Caucasian, 22 Afro-Caribbean and two Oriental), and 21 women (five Caucasian, 12 Afro-Caribbean and two Oriental). Concentric hypertrophy was present in 46% of subjects, concentric remodelling in 32% of subjects, eccentric hypertrophy in only 6% of subjects and a normal left ventricular shape in 16% of subjects. The degree of sphericity of the left ventricle was similar among the four groups, suggesting that it does not change in uncomplicated hypertension. In contrast to the previously published combined series from Sassari and New York we had a low proportion of patients with either eccentric hypertrophy or normal left ventricular geometry. This is probably due to the high proportion of Afro-Caribbean subjects in our clinic population who are more likely to have left ventricular hypertrophy.

Left ventricular hypertrophy, blood pressure and ACE genotype in untreated hypertension

It has been suggested that the deletion polymorphism of the angiotensin-converting enzyme (ACE) genotype may be important in the development of left ventricular hypertrophy (LVH). In order to test this hypothesis we investigated the interaction between blood pressure (BP), LVH and ACE genotype in 86 previously untreated hypertensive patients. Each underwent two-dimensional and Doppler echocardiography and ACE genotyping. There were no significant differences in BP, the parameters of left ventricular structure (including left ventricular mass index) or diastolic function between the three genotype groups. Additionally, there were no significant differences in the relationship between systolic BP and left ventricular mass index among the three genotype groups (II genotype, r = 0.46, P = 0.02; ID genotype, r = 0.42, P = 0.01; DD genotype, r = 0.34, P = 0.10; F = 0.38). In contrast to some previous studies, we have found in this group of previously untreated hypertensive subjects no evidence to suggest that the deletion polymorphism of the ACE genotype is important in the development of LVH.

Platelet aggregability and occurrence of restenosis following coronary angioplasty

Restenosis following percutaneous coronary angioplasty (PTCA) is a complex medical problem occurring in nearly a third of the patients undergoing PTCA with no single definite predictor demonstrated in an individual patient. Platelets are known to play an important role in the pathogenesis of the restenotic process. However, no known parameter of platelet function or activity has been studied as a risk factor predicting the occurrence of restenosis. We prospectively assessed platelet activation in twenty two consecutive patients with stable angina who underwent a successful PTCA for single vessel coronary artery disease. Platelet activation levels were measured using aggregability curves derived from unclotted blood samples on a platelet aggregometer using varying concentrations of adenosine di-phosphate (ADP) in the following time sequence: (1) Basal i.e. pre-PTCA, (2) post-PTCA day 1, (3) post-PTCA day 7, and (4) post-PTCA day 28. Occurrence of restenosis was studied using angiographic follow-up in all patients. At follow-up, seven of the twenty two patients studied developed restenosis. There was no significant difference or any specific trend noted over time in the levels of platelet aggregability in the study group as a whole (basal: 30.0 +/- 15.4%, post-PTCA day 1: 32.5 +/- 16.1%, post-PTCA day 7: 34.6 +/- 15.4% and post-PTCA day 28: 32.6 +/- 16.1%). However, when the patients were subgrouped into those with and without restenosis, the patients with restenosis had a significantly higher basal platelet aggregability (38.7 +/- 16.3%) versus those who did not develop restenosis (25.0 +/- 12.1%), p = 0.0128. We conclude that patients developing restenosis after PTCA have a significantly higher basal platelet aggregability and this could be used as a marker for its occurrence in an individual patient.

Absent conal septum in tetralogy of Fallot. An angiographic study

Absent conal septum in tetralogy of Fallot (TF) is usually noted intraoperatively when the ventricular septal defect (VSD) is found abutting the pulmonary valve, its superior rim being nearly inaccessible transatrially, and the posterior rim being separated from the tricuspid valve (TV) by a muscular ridge. The authors retrospectively analyzed angiograms of 208 consecutive patients with TF seen at their center from July 1989 to December 1995 for absence of the conal septum and the presence of an interval between the TV and the margin of the VSD in 30 degrees right anterior oblique view. In 13 (6%) patients, angiograms were inadequate or of poor quality for assessment and were excluded. Twenty-two of the remaining 195 (11%) patients had a large muscular interval between the tricuspid annulus and the margin of the VSD, which was associated with an absent conal septum in 14 (7.2%) and a diminutive septum in 8 (4%) patients. Nine of the 14 patients with an absent conal septum at angiography underwent surgery, and this finding was confirmed in all. The authors conclude that absent conal septum is not uncommon in TF and constitutes an important variation in its anatomy that can be identified preoperatively at angiography for optimal surgical management.

The effects on cardiac arrhythmias of antihypertensive therapy causing regression of left ventricular hypertrophy

To examine the effects of antihypertensive therapy causing regression of left ventricular hypertrophy on cardiac arrhythmias, 26 hypertensive subjects were treated with ramipril with felodipine if required, and followed for 6 months after blood pressure control. Compared with baseline, left ventricular mass index (LVMI) was significantly reduced both at blood pressure control and after a further 6 months of treatment (baseline, blood pressure control, 6 months after blood pressure control; LVMI 142 +/- 3.6, 131 +/- 3.4, 123 +/- 3.8* g/m2, *P < .01 compared with baseline). There was a significant relationship between the decrease in systolic blood pressure and the decrease in LVMI after 6 months of blood pressure control compared with baseline (r = 0.41, P = .05). Compared with baseline, the average total number of ventricular ectopics decreased after blood pressure was controlled (88 +/- 59 and 21 +/- 12 respectively); however this reduction was not maintained after 6 months of further treatment, either before (78 +/- 50) or after drug washout (86 +/- 40). Compared with baseline (639 +/- 590) supraventricular ectopic total was not initially reduced after blood pressure control (650 +/- 604), but was reduced after a further 6 months of treatment (294 +/- 261). This reduction was maintained after drug washout (267 +/- 254), although this did not reach statistical significance. Radionuclide scanning at baseline was not a predictor of patients with the highest risk of arrhythmia and there was no correlation between improvement or worsening of a defect with changes in ventricular ectopic total. In conclusion, antihypertensive therapy with ramipril and felodipine, although causing regression of left ventricular hypertrophy did not lead to a sustained reduction in ventricular ectopic total.

Left ventricular hypertrophy and QT dispersion in hypertension

The interlead variation in QT length on a standard electrocardiograph reflects regional repolarization differences in the heart. To investigate the association between this interlead variation (QT dispersion) and left ventricular hypertrophy, we subjected 100 untreated subjects to 12-lead electrocardiography and echocardiography. Additionally, 24 previously untreated subjects underwent a 6-month treatment study with ramipril and felodipine. In the cross-sectional part of the study, QT dispersion corrected for heart rate (QTc dispersion) was significantly correlated with left ventricular mass index (r = .30, P < .01), systolic pressure (r = .30, P < .01), the ratio of peak flow velocity of the early filling wave to peak flow velocity of the atrial wave (E/A ratio) (r = -.22, P = .02), isovolumic relaxation time (r = .31, P < .01), and age (r = .21, P < .04). In the treatment part of the study, lead-adjusted QTc dispersion decreased from 24 to 19 milliseconds after treatment, and after a subsequent 2 weeks of drug washout remained at 19 milliseconds (P < .01). The changes in left ventricular mass index at these stages were 144, 121, and 124 g/m2 (P < .01). Systolic pressure decreased from 175 to 144 mm Hg and increased again to 164 mm Hg after drug washout (P < .01). The E/A ratio (0.97, 1.02, and 1.02; P = 69) and isovolumic relaxation time (111, 112, and 112; P = .97) remained unchanged through the three assessment points. In conclusion, QT dispersion is increased in association with an increased left ventricular mass index in hypertensive individuals. Antihypertensive therapy with ramipril and felodipine reduced both parameters. If an increased QT dispersion is a predictor of sudden death in this group of individuals, then the importance of its reduction is evident.

Transesophageal dobutamine-atropine stress echocardiography: diagnostic accuracy for coronary stenosis detection and localization

Transesophageal echocardiography with dobutamine-atropine stress (TE-DASE) is a recently described technique for evaluation of coronary artery disease (CAD). We undertook this study prospectively to determine the feasibility, reliability and safety of this procedure in patients with known CAD and to evaluate its diagnostic accuracy for coronary stenoses of varying severity. Thirty-seven patients who underwent coronary arteriography (CART) and TE-DASE within a 3-month interval without intervening ischemic events or revascularisation were included in the study CART and stress echograms were independently evaluated by different observers. Stenosis was measured with calipers and a > or = 50% lumen diameter stenosis was considered significant. A reduction or lack of endocardial motion and/or wall thickening on progressive incremental stress was considered an abnormal response. TE-DASE could be successfully completed in 33/37 (90%) patients. Using a modified 16-segment model of the left ventricle (LV), 15.2 +/- 0.8 segments/patient and 501/528 (95%) segments overall could be optimally evaluated. Inter-observer concordance for an abnormal response was 94%. Predictive accuracies for one-vessel disease (1-VD), two-vessel disease (2-VD) and three-vessel disease (3-VD) were 88, 58 and 23% respectively. Overall sensitivity for detection of a significant (> or = 50%) stenosis was 72% (32% for moderate (50-69%), 90% for severe (> or = 70%) stenosis) and specificity was 96%. Diagnostic accuracy for localisation of significant stenosis was 95% for the left anterior descending artery (LAD), 86% for the left circumflex artery (LCX) and 88% for the right coronary artery (RCA). There were no major complications. We conclude that TE-DASE is a safe, reliable and easily-performed procedure and provides excellent visualisation of myocardial segments. Diagnostic accuracy for detection of severe stenosis and its localisation is excellent.

Plasma mediated neutrophil stimulation during coronary angioplasty: autocrine effect of platelet activating factor

BACKGROUND

Polymorphonuclear neutrophils are involved in the development of myocardial injury during ischaemia and reperfusion. Coronary angioplasty has been shown to result in neutrophil activation. This may be a result of contact with ligands expressed by endothelial cells or response to soluble stimuli released from ischaemic tissue into the plasma or both.

OBJECTIVE

To investigate plasma mediated neutrophil activation during angioplasty.

METHODS AND RESULTS

Plasma samples were collected from the coronary sinus, femoral artery, and femoral vein of 14 patients undergoing angioplasty, before and after the first balloon inflation and at the end of the procedure. Plasma samples were incubated with washed neutrophils isolated from healthy donors. Expression of the adhesion molecules CD18 integrin and L-selectin (Leu-8) was measured by flow cytometry, and superoxide anion production was measured by chemiluminescence. Plasma samples from the coronary sinus and femoral artery but not from the peripheral vein induced increased expression of neutrophil CD18 after balloon deflation. Modification of the expression of L-selectin was not noted. Production of superoxide anion by neutrophils was stimulated by plasma samples from the coronary sinus, but not by those from the femoral artery or vein. This plasma mediated neutrophil stimulation was prevented when the neutrophils were pretreated with platelet activating factor receptor antagonists BN52021 or BN50739. The platelet activating factor concentration detected in the coronary sinus was not higher than in control plasma.

CONCLUSION

Brief ischaemia during coronary angioplasty leads to the release of soluble stimuli capable of inducing neutrophil integrin expression and free oxygen radical production. Platelet activating factor may act as an autocrine neutrophil stimulus under these conditions.

The effects of antihypertensive therapy on carotid vascular structure in man

OBJECTIVE

An increased carotid intima-media thickness (IMT) has been found to be associated with a number of cardiovascular risk factors such as age, hypertension, cigarette smoking, hypercholesterolaemia and left ventricular hypertrophy. Our objective was to assess whether carotid intima-media thickness in hypertensive patients could be reduced by antihypertensive therapy.

METHODS

13 hypertensive patients, 10 previously untreated, were examined using carotid ultrasonography and echocardiography at baseline and then at 8 weeks and 39 weeks after commencement of antihypertensive therapy with ramipril and the second-line addition of felodipine.

RESULTS

By the end of the study significant regression of IMT (0.1(0.05-0.16) mm, F-value 10.2, P < 0.01) and left ventricular mass index had occurred (25(10.7-39.3) g/m2, F-value 9.7, P < 0.01). The reduction in IMT was significantly related to the reduction in mean arterial pressure, r = 0.55, P = 0.05).

CONCLUSION

Antihypertensive therapy with ramipril and felodipine causes regression of IMT in hypertensive patients, probably chiefly through blood pressure reduction. Large prospective studies are required to assess whether a reduction in IMT results in a reduction in morbidity and mortality.

Left ventricular diastolic function in hypertension: a 4 year follow-up study

In order to assess the long term effects of antihypertensive treatment on left ventricular diastolic function, 26 hypertensive patients were followed up for a mean of 4.25 years with two-dimensional and Doppler echocardiography. A significant reduction in left ventricular mass index was first apparent after 9 months of therapy (mean (S.D.) 124 (22) vs. 114 (18) g/m2, P < 0.01), and this was maintained over the 4.25 year period (124 (22) vs. 117 (17) g/m2, p < 0.05). At 9 months there was no change in either isovolumic relaxation time (108 (26) vs. 108 (17) ms, P = N.S.) or left ventricular filling as assessed by peak flow velocity E/A ratio (0.94 (0.22) vs. 0.95 (0.27), P = N.S.). However, after 4.25 years there was a significant improvement in IVRT (108 (26) vs. 83 (11) ms, P < 0.01) with a trend towards an improved peak flow velocity E/A ratio, although this did not reach statistical significance (0.95 (0.27) vs. 1.02 (0.26), P = N.S.). Of the 14 patients who had an abnormal isovolumic relaxation time at baseline, 12 normalised and 2 improved. These findings suggest that left ventricular diastolic dysfunction in hypertension may be reversed by prolonged antihypertensive treatment.

Left ventricular structure and function in previously untreated hypertensive patients: the importance of blood pressure, the nocturnal blood pressure dip and heart rate

BACKGROUND

Cardiac assessment is an important part of risk stratification in hypertensive patients. Left ventricular hypertrophy in particular is a powerful predictor of subsequent cardiovascular morbidity and mortality. Previous studies assessing haemodynamic factors that may be responsible for cardiac changes in hypertensive patients have been performed in those previously treated for hypertension. To investigate more fully these haemodynamic relationships, a large group of previously untreated patients were studied.

METHODS

Ninety-eight previously untreated hypertensive patients underwent electrocardiography, two-dimensional and Doppler echocardiography, 24 h ambulatory blood pressure monitoring and exercise stress testing.

RESULTS

The left ventricular mass index (LVMI) was more closely related to mean 24 h than to clinic blood pressures (24 h systolic r = 0.48, P < 0.01; 24 h diastolic r = 0.49, P < 0.01; clinic systolic r = 0.28, P < 0.01; clinic diastolic r = 0.31, P < 0.01). In addition, the systolic nocturnal blood pressure dip was found to be inversely related to LVMI in men (r = -0.32, P < 0.01). Of the indices of left ventricular diastolic function, age (r = -0.64, P < 0.01), heart rate (r = -0.25, P = 0.02) and LVMI (r = -0.22, P = 0.02) were independently related to the E-A ratio. Age (r = 0.40, P < 0.01), blood pressure (systolic r = 0.39, P < 0.01; diastolic r = 0.43, P < 0.01), the nocturnal blood pressure dip (systolic r = -0.38, P < 0.01, diastolic r = -0.31, P < 0.01) and LVMI (r = 0.37, P < 0.01) were independently related to the isovolumic relaxation time.

CONCLUSIONS

Blood pressure was the only independent determinant of LVMI; nocturnal blood pressure may be particularly important in men. Age and both haemodynamic and structural factors are independent determinants of parameters of left ventricular diastolic function in hypertensive patients.

Ventricular arrhythmias in hypertension: in which patients do they occur?

OBJECTIVE

It has been suggested that the increased incidence of sudden death in hypertensive patients, particularly those with left ventricular hypertrophy, may be casually related to the increased number and complexity of ventricular arrhythmias that have been demonstrated in these patients. The objective of the present study was to assess some of the factors which might be responsible for these arrhythmias.

SUBJECTS AND METHODS

One hundred and three untreated subjects were divided into four groups on the basis of blood pressure and echocardiographic measurements: hypertensive patients with left ventricular hypertrophy (n = 38), hypertensive patients without left ventricular hypertrophy (n = 16), patients with borderline or white-coat hypertension (n = 26) and normotensive subjects (n = 23). Each subject underwent two-dimensional and Doppler echocardiography, 12-lead electrocardiogram examination, 12-lead electrocardiogram exercise stress testing, 24-h ambulatory blood pressure monitoring and 24-h Holter monitoring. A further 17 hypertensive patients with left ventricular hypertrophy who were on long-term antihypertensive therapy were also investigated in the same manner and compared with untreated hypertensive patients with left ventricular hypertrophy who were matched for age, sex and race.

RESULTS

Untreated hypertensive patients, even with left ventricular hypertrophy, had a low prevalence of frequent or complex arrhythmias (seven out of 80 patients with Lown score 2+). In contrast, hypertensive patients with left ventricular hypertrophy on long-term antihypertensive therapy had a significantly greater prevalence of complex arrhythmias than untreated patients with left ventricular hypertrophy (eight out of 17 treated patients compared with two out of 17 untreated patients with Lown score 2+).

CONCLUSIONS

Hypertensive patients with left ventricular hypertrophy who had received long-term antihypertensive therapy were found to have a high prevalence of complex ventricular arrhythmias, which was in contrast to untreated hypertensive patients, even those with left ventricular hypertrophy. This may reflect the consequences on the left ventricle of long-term antihypertensive treatment. If complex ventricular arrhythmias are implicated in the excess of sudden deaths in hypertensive patients, this might be an important factor.

Structural changes in the cardiovascular system of untreated essential hypertensives

Arterial hypertension is associated with structural changes in the cardiovascular system. This study has examined the effect of hypertension on the carotid artery wall and examined the relation between changes in the structure of carotid artery wall and left ventricle in untreated hypertensives. The carotid artery wall was visualized using a high resolution ultrasound technique in 37 untreated hypertensive patients (25 males, 12 females) and 37 age and sex matched normotensive individuals and carotid intima-media thickness (IMT) and carotid artery diameter measured. IMT and intima-media cross sectional area was significantly greater in the hypertensive group compared with the normotensive group, though the carotid artery diameter did not differ significantly. There was a significant association between age and IMT in both groups. In the hypertensive group there was also a significant association between left ventricular mass index, ventricular septal or posterior wall thickness and IMT. This study indicates that there is an association between cardiac and carotid arterial structure in hypertension. Such a relationship may be important in understanding the associated risks of high blood pressure.

Replacement treatment with biosynthetic human growth hormone in growth hormone-deficient hypopituitary adults

OBJECTIVES

The physiological role of growth hormone in adult life has recently attracted increased interest. We have studied the clinical effects and the effects on body composition of prolonged replacement with biosynthetic human GH in a large number of hypopituitary adults.

DESIGN

A randomized double blind placebo controlled trial for 6 months followed by an open trial of GH treatment for 12 months. GH daily dose was 0.04 (0.02-0.05) IU/kg s.c.

PATIENTS

Forty GH deficient hypopituitary patients (19 M, 21 F; aged 19-67 years) on conventional replacement therapy were studied.

MEASUREMENTS

Serum insulin like growth factor I (IGF-I), skinfold thickness, total body potassium, total body water (TBW), exercise tolerance and muscle strength, and well-being.

RESULTS

During the 6-month double blind phase, two GH treated patients withdrew because of adverse events. Lean body mass (LBM) increased and percentage body fat (%BF) decreased on GH but not on placebo (P) (LBM: (GH: from 48.5 +/- 9.6 to 49.6 +/- 9.5 kg; P: from 50.9 +/- 9.2 to 50.1 +/- 9.0 kg, P < 0.05 GH vs P) and %BF (GH: from 34.7 +/- 11.4 to 34.2 +/- 10.7; P: from 37.4 +/- 7.6 to 38.7 +/- 8.1, P < 0.05 GH vs P)). TBW increased on GH (P < 0.01) but not on P. No change was observed in waist-to-hip ratio or in muscle strength. During longer-term follow-up combining the double blind and open phase components of the study, 34, 27 and 11 patients received GH for 6, 12 and 18 months respectively. Patients dropped out because of adverse events or lack of perceived benefit. Skinfold thicknesses decreased significantly at 6 and 12 months and the waist circumference at 6 months. Waist-to-hip ratio decreased significantly on GH at 12 months. LBM increased on GH treatment from 49.6 +/- 9.1 to 51.6 +/- 9.4 kg (P < 0.0006), 51.9 +/- 8.9 kg (P < 0.07) and 53.1 +/- 10.5 kg (P < 0.0001) at 6, 12 and 18 months respectively. Percentage body fat decreased on GH from 37.2 +/- 10.7 to 34.7 +/- 10.1 (P < 0.005), 35.1 +/- 12.8 (NS) and 34.5 +/- 8.6 (P < 0.04) at 6,12 and 18 months respectively. TBW also increased at 6 and 12 months of GH treatment. Exercise time increased significantly at 6, 12 and 18 months of GH treatment. Muscle strength in selected muscle groups increased significantly at 6, 12 or 18 months of GH treatment. Randomization resulted in the placebo group having a greater GHQ score (higher morbidity) than the GH group before therapy. Over the controlled phase, GHQ scores improved on placebo but not on GH and CPRS score was unchanged in either group. In the open phase, the GHQ score did not change on GH therapy but CPRS score improved at 6 and 12 months.

CONCLUSIONS

Growth hormone replacement therapy in adults for 6 months increased lean body mass, total body water and exercise tolerance, and decreased body fat. Growth hormone replacement for longer than 6 months maintains the advantageous effects seen in shorter-term studies and may have additional effects on body fat distribution, muscle strength and psychological well-being.

Cardiovascular effects of prolonged growth hormone replacement in adults

OBJECTIVES

To study the cardiovascular effects of human growth hormone (GH) replacement therapy in adults.

INTERVENTION

Biosynthetic human GH given in a daily dose of 0.04 +/- 0.01 IU kg-1 for 6-18 months in an open trial.

PATIENTS

Thirty-four GH-deficient hypopituitary patients on conventional replacement therapy, aged 19-67 years and with a body mass index of 18.0-410.0 kg/m2.

MEASUREMENTS

Resting blood pressure, exercise tolerance, renal function and routine blood counts were assessed every 6 months. Two-dimensional echocardiography and Doppler ultrasound scanning were performed at 0, 6 and 12 months of GH therapy.

RESULTS

Exercise time increased significantly on GH from 9.37 +/- 2.64 min at the start to 10.39 +/- 2.86 min (P < 0.001), 10.90 +/- 2.48 min (P < 0.001) and 11.11 +/- 0.70 min (P < 0.001) at 6, 12 and 18 months respectively. There was no change in the heart rate or in the blood pressure at rest nor at the peak of exercise. No significant changes were observed in measures of cardiac structure (left ventricular mass index, left ventricular posterior wall thickness and interventricular septal thickness), ejection fraction nor in cardiac output. Isovolumic relaxation time, a marker of diastolic function, decreased in 24 patients after 6 months on GH (from 98.6 +/- 15.9 to 89.6 +/- 15.2 ms; P < 0.03) but it was not different from baseline in the 18 patients who were restudied at 12 months. There was no significant change in the left ventricular filling neither at 6 nor at 12 months. No significant, changes were observed in plasma electrolytes, creatinine nor in blood count on GH treatment.

CONCLUSIONS

Growth hormone replacement therapy in hypopituitary adults for 6-18 months produced sustained increase in exercise tolerance but was not associated with changes in cardiac structure or systolic function.

Cardiovascular effects of growth hormone replacement therapy in hypopituitary adults

In the present study the effects of replacement with biosynthetic human growth hormone (GH) in a large group of hypopituitary adults on cardiac structure and function were investigated. Thirty-six GH-deficient, hypopituitary patients (17 males and 19 females; aged 19-67 years) on conventional replacement therapy without GH were studied. Twenty-nine of the patients had acquired hypopituitarism in adult life, mainly due to pituitary tumours. The design of the study was a prospective, randomized, double-blind placebo-controlled trial for 6 months. Growth hormone (17 patients) was given in a daily dose of 0.02-0.05 IU/kg body wt sc (or a placebo, 19 patients) according to the patients' tolerance. Other pituitary replacement treatment was unchanged. Resting and exercise electrocardiography using the Bruce protocol, two-dimensional echocardiography, Doppler ultrasound scanning and serum insulin-like growth factor I (IGF-I) were assessed at 0 and 6 months. Resting blood pressure was measured at 0, 1, 3 and 6 months. Serum IGF-I increased significantly on GH treatment (mean +/- SD) GH: 293 +/- 197 vs placebo: 82 +/- 40 micrograms/l; p < 0.0001 at 6 months). Exercise time increased significantly on GH but not on placebo (GH: 8.45 +/- 3.16 to 9.38 +/- 2.42 min.sec, p < 0.01; placebo 9.08 +/- 4.35 to 9.50 +/- 4.14 min.sec, NS), although the change was not significantly different between the two. There was no change in the heart rate or the blood pressure either at rest or at the peak of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Racial differences in cardiac structure and function in essential hypertension

OBJECTIVE

To assess racial differences in cardiac structure and function in patients presenting with previously untreated hypertension.

DESIGN

Untreated black patients with hypertension were compared with untreated white patients matched for age and sex. Both groups had similar body mass indices, blood pressures, and reported duration of hypertension.

SETTING

Cardiovascular risk factor clinic for outpatients.

SUBJECTS

36 men and 22 women with untreated essential hypertension.

MAIN OUTCOME MEASURES

Variables of heart structure and function on cross sectional and Doppler echocardiography.

RESULTS

The black patients had a significantly greater interventricular septal thickness (mean 1.23 (95% confidence interval 1.14 to 1.33) v 1.09 (1.02 to 1.16) cm; P = 0.02) and posterior wall thickness (mean 1.14 (1.07 to 1.22) v 0.96 (0.88 to 1.03) cm; P = 0.001) than the white patients, although left ventricular internal diameter was not significantly different (mean 4.90 (4.68 to 5.12) v 4.82 (4.64 to 5.01) cm; P = 0.59). This resulted in a significantly greater left ventricular mass index (mean 151 (137 to 164) v 120 (107 to 133) g/m2; P = 0.001) and relative wall thickness (mean 0.47 (0.43 to 0.51) v 0.40 (0.37 to 0.42) cm; P = 0.004) in the black patients. Comparison of Doppler measures of left ventricular diastolic function showed a significantly longer isovolumic relaxation time in black patients (mean 107 (98 to 116) v 92 (83 to 101) ms; P = 0.02) compared with white patients, although peak early to atrial filling ratios were similar in both groups (mean 1.14 (0.95 to 1.32) v 1.04 (0.94 to 1.15); P = 0.37).

CONCLUSION

Among previously untreated hypertensive patients, black subjects compared with white subjects have significantly higher left ventricular mass index and relative wall thickness, as well as more impairment of left ventricular function during diastole.

Structural changes in the heart and carotid arteries associated with hypertension in humans

Hypertension is associated with structural changes in the vascular system and in the heart. This study has examined the relationships between carotid artery intima-media thickness and other risk factors in 52 untreated patients (20 hypertensive). Carotid intima-media thickness was measured bilaterally using a Duplex doppler ultrasonic scanner. In the hypertensive individuals the left ventricle was examined by echo-cardiography and the left ventricular mass index determined. There was a significant association between age and IMT, and both SBP and DBP and IMT. The IMT in the hypertensive group was significantly larger than in the normotensive group and in the hypertensive subjects there was a positive association between left ventricular mass index and IMT. There was no significant difference in calculated media stress between the normotensive and hypertensive groups, probably due to a small increase in carotid intima-media area combined with a small reduction in carotid lumen diameter. Hypertension is associated with a thickening of the intima-media of the carotid artery and an increase in left ventricular mass. Whether these changes in cardiac and arterial structure are in response to similar influences remains to be established.

Effectiveness and safety of a single intravenous bolus injection of tissue-type plasminogen activator in acute myocardial infarction. Bolus Dose-Escalation Study of Tissue-Type Plasminogen Activator (BEST) Investigators

The efficacy of multiple intravenous bolus injections of tissue-type plasminogen activator (t-PA) in inducing rapid coronary recanalization in patients with acute myocardial infarction was previously demonstrated. In this Bolus Dose-Escalation Study of Tissue-Type Plasminogen Activator (BEST), the efficacy of 3 different doses of a single rapid intravenous bolus injection of t-PA (dute-plase, Wellcome Foundation, London) in inducing coronary patency (Thrombolysis In Myocardial Infarction perfusion grade 2 or 3) in 64 patients with acute myocardial infarction presenting less than 6 hours after onset of symptoms was investigated. At 60 minutes after administration of t-PA, the infarct-related coronary artery was patent in 9 of 17 patients (53%; 95% confidence interval [CI] 28 to 77%) after 0.3 MU/kg, in 14 of 23 (61%; 95% CI 39 to 80%) after 0.45 MU/kg and in 10 of 14 (71%; 95% CI 42 to 92%) after 0.6 MU/kg. At 90 minutes after t-PA, coronary patency was present in 9 of 17 cases (53%; 95% CI 28 to 77%) after 0.3 MU/kg, in 12 of 24 (50%; 95% CI 29 to 71%) after 0.45 MU/kg and in 10 of 13 (77%; 95% CI 46 to 95%) after 0.6 MU/kg. One patient in each dose group had a silent reoccluded infarct-related artery by 24 hours, and there were 2 clinical reinfarctions before discharge. No major bleeding events were observed. There were 5 hospital deaths, all unrelated to t-PA. A single intravenous bolus injection of 0.6 MU/kg of t-PA appears to be effective in inducing rapid coronary patency and to be safe in patients with acute myocardial infarction.

Metabolic changes and vascular risk factors in hypopituitarism

Adults with hypopituitarism die prematurely, and the excess mortality is from vascular disease. On echocardiography we have demonstrated abnormalities of myocardial diastolic function in hypopituitary adults, indicating possible early ischaemic change. Peripheral arterial disease is evident on ultrasonography. Vascular risk factors have also been examined. Impaired glucose tolerance and unrecognized diabetes are common in hypopituitary adults. Total cholesterol levels are elevated, particularly in hypopituitary women. The role of growth hormone (GH) deficiency in the vascular disease and in the vascular-risk-factor abnormalities is unknown at present. Prolonged GH therapy causes a decrease in the levels of fasting total cholesterol, without any adverse effects on glucose homeostasis. GH therapy trials in adults will clarify the role of GH in the excess vascular risk of hypopituitarism. Prolonged GH therapy will be necessary for the vascular effects to be defined.

Myocardial dysfunction in treated adult hypopituitarism: a possible explanation for increased cardiovascular mortality

OBJECTIVE

To assess cardiac structure and function in patients with treated hypopituitarism and to determine their relation to the degree of growth hormone deficiency and body composition pattern.

DESIGN

26 patients with treated hypopituitarism were studied by cross sectional and Doppler echocardiography and by exercise testing. The results were analysed and their relation to the degree of growth hormone deficiency and body composition determined.

SETTING

All tests were performed in the department of cardiology and the unit of metabolic medicine at a tertiary referral centre.

PATIENTS

Patients with hypopituitarism referred for endocrine assessment.

MAIN OUTCOME MEASURES

Left ventricular mass, left ventricular diastolic function, and exercise capacity in patients with hypopituitarism and their relation to growth hormone deficiency.

RESULTS

Mean (SD) serum concentration of insulin-like growth factor 1 (IGE-1), a measure of growth hormone deficiency, was 82.4 (45) micrograms/l. Lean body mass calculated by measuring total body potassium was 50 (9) kg. All patients had a normal left ventricular mass index and a normal left ventricular ejection fraction. Eight patients had abnormal left ventricular diastolic function. There was a significant correlation between IGF-1 and left ventricular mass (r = 0.45, p less than 0.02). Lean body mass was also significantly correlated with left ventricular mass (r = 0.78, p less than 0.0001) and left ventricular diastolic function (r = -0.63, p less than 0.01). The mean exercise duration was 8.6 (3.6) minutes. There was a significant correlation between serum IGF-1 and the rate-pressure product on exercise (r = 0.47, p less than 0.01). Seven patients had planar ST segment depression greater than 0.1 mV during exercise testing. In five of these patients there was rapid resolution of ST segment depression immediately after exercise. Two patients developed considerable ST segment depression, and subsequent coronary angiography showed normal coronary arteries. Exercise-induced ST segment depression was not related to the severity or duration of growth hormone deficiency or serum cholesterol concentration.

CONCLUSIONS

This study suggests that left ventricular mass and the rate-pressure product are related to the degree of growth hormone deficiency, that left ventricular diastolic dysfunction is frequently seen in hypopituitarism, and that these patients may have ischaemic-like ST segment changes during exercise testing. These findings may explain the increased cardiovascular mortality in patients with hypopituitarism and may also have implications for growth hormone replacement therapy in adults.

Impaired left ventricular filling during ST-segment depression provoked by dipyridamole infusion in patients with syndrome X

The left ventricular filling and regional wall motion patterns were compared in 6 normal subjects, 20 patients with coronary artery disease, and 10 patients with syndrome X by means of Doppler and two-dimensional echocardiography during high-dose (0.9 mg/kg body weight in 10 min) dipyridamole infusion. During the procedure none of the normal subjects had chest pain or significant ST depression (greater than 0.1 mV) whereas 10 of 20 patients with coronary artery disease had ST depression, 3 with chest pain. Six patients with syndrome X had ST depression, 5 with chest pain. Regional wall motion abnormalities were identified in 6 patients with coronary artery disease who had ST depression but none were detected in normals or in patients with syndrome X. Compared with normals (-2.1 +/- 3.5%) there was a significant difference in percentage decrease in the peak early filling velocity in patients with coronary artery disease and ST depression (-10.3 +/- 6.2%; p less than 0.01) and in patients with syndrome X and ST depression (-9.4 +/- 6.9%; p less than 0.05). These findings indicate that, in the presence of dipyridamole-induced ST depression, patients with syndrome X have an abnormal left ventricular filling pattern similar to that observed in patients with coronary artery disease. This suggests that myocardial ischemia occurs in patients with syndrome X but the absence of regional wall motion abnormality suggests that it is diffuse.

The effects of blood pressure reduction on abnormal left ventricular diastolic function in hypertensive patients

To investigate whether reduction in blood pressure has a beneficial effect on left ventricular diastolic function, we investigated 20 hypertensive patients with evidence of diastolic dysfunction at baseline and at 3 and 6 months after initiation of captopril therapy. Two-dimensional echocardiography was used to determine left ventricular mass index and Doppler ultrasound to assess diastolic function. Fifteen of the 20 patients had a significant reduction in blood pressure at 3 and 6 months and left ventricular mass index remained unchanged during the study period. Despite reduction in blood pressure, no difference in isovolumic relaxation time, early and atrial filling velocities or their ratio was observed. Our results suggest that a direct relationship between blood pressure and left ventricular diastolic function does not exist and that other factors such as alterations in muscle or collagen composition of the left ventricle may be more important in determining abnormal diastolic function in hypertension.