Increased left ventricular mass in salt-sensitive hypertensive patients

Clinical, biochemical and echocardiographic characteristics were evaluated from 50 essential hypertensive patients classified asccording to their salt-sensitivity status. Salt-sensitive hypertension was diagnosed by means of ambulatory blood pressure monitoring (ABPM) in 22 (44%) patients showing a significant increase in mean BP (P < 0.05) from a 7-day period of low salt (20 mmol NaCl/day) intake, to a 7-day period of high salt (260 mmol NaCl/day) intake. The remaining 28 (56%) patients were considered as having salt-resistant hypertension. Compared with salt-resistant patients, salt-sensitive ones showed an increased left ventricular mass index (P = 0.0118), septal (P = 0.0021) and posterior wall thickness (P = 0.0026), without differences in the internal diastolic diameter. Decreased values of HDL-cholesterol (P = 0.0475) and increased total cholesterol/HDL-cholesterol ratio (P = 0.0098) were also observed in the salt-sensitive, compared with the salt-resistant hypertensive patients. Age, gender, body mass index, systolic and diastolic BP, fasting plasma glucose, creatinine and uric acid did not differ between salt-sensitive and salt-resistant patients. We conclude that, at the same level of BP, salt-sensitive patients exhibit an increased prevalence of left ventricular hypertrophy and a worse lipid profile. These two aspects may confer to salt-sensitive patients an increased risk in terms of cardiovascular morbidity and mortality.     

Electrocardiographic left ventricular hypertrophy in chest pain patients: differentiation from acute coronary ischemic events

Electrocardiographic left ventricular hypertrophy (LVH) and related repolarization changes alter the morphology of the ST segment and/or the T wave. Such electrocardiographic abnormalities--all features that are encountered in patients with acute ischemic heart disease--may confound the early emergency department evaluation of the chest pain patient. In the instance of the chest pain patient demonstrating ST segment/T wave abnormality, the correct electrocardiographic diagnosis must be made not only to offer appropriate management for that particular illness but also to avoid the incorrect application of potentially dangerous therapies such as thrombolysis. This report presents two cases in which the electrocardiogram demonstrated significant repolarization changes consistent with LVH, and focuses on the recognition of the expected ST segment/T waves changes and their differentiation from the primary ST segment/T wave changes associated with acute ischemic heart disease.     

Mechanism of impaired left ventricular wall motion in the diabetic heart without coronary artery disease

OBJECTIVE: To elucidate whether impairment of the myocardial free fatty acid (FFA) metabolism and small vessel abnormalities in the myocardium are etiologic or contributory factors of myocardial dysfunction in patients with NIDDM without any significant coronary artery disease. RESEARCH DESIGN AND METHODS: We performed myocardial imaging with 123I-labeled beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a branched analog of FFA, and dipyridamole-infusion 201thallium scintigraphy (Dip) in nine patients who demonstrated left ventricular wall motion abnormalities without any significant coronary artery disease and in fifteen control cases. As an index of myocardial FFA metabolism, the heart-to-mediastinum count ratio (H/M) of BMIPP was calculated from the mean count in the regions of interest at the heart and the upper mediastinum. RESULTS: Nine patients with reduced wall motion documented by left ventriculography (LVG), (hypokinetic group) demonstrated significantly lower BMIPP uptake (2.1 +/- 0.2, mean +/- SD) than fifteen patients with normal wall motion (normokinetic group) (2.3 +/- 0.2, P < 0.05). Regional ventricular wall motion observed by LVG, regional BMIPP uptake, and regional redistribution phenomenon (RD) were evaluated for five regions of the left ventricle: anterior, septal, apical, lateral, and inferoposterior regions. Wall motion was abnormal in 24 out of 120 regions. Regional BMIPP uptake was reduced in 47 regions. RD in Dip was observed in 23 regions. In regional analysis, the existence of defect in the BMIPP image showed significant correlation with wall motion abnormality (P < 0.01), but there was no significant relationship between the RD in Dip and regional wall motion abnormality (P = 0.16). Myocardial biopsy specimens obtained from the right ventricle of 20 patients showed no pathologic changes, with the exception of two patients. CONCLUSIONS: Our findings suggest that impairment of myocardial FFA metabolism rather than small vessel abnormalities in the myocardium is responsible for modest left ventricular dysfunction in patients with diabetes.     

Long-term effects of delapril hydrochloride on procollagen type III amino-terminal peptide, left ventricular mass and left ventricular function in hypertensive patients

The long-term effect of delapril hydrochloride, a non-sulfhydryl angiotensin converting enzyme inhibitor, on serum concentrations of procollagen type III amino-terminal peptide (PIIIP) and left ventricular mass (LVM) and function were investigated in 15 hypertensive patients. Patients were treated with delapril hydrochloride 30 mg/day po for 12 months. Blood samples and an echocardiogram were obtained before treatment and after 6 and 12 months of treatment. Blood pressure, PIIIP, and LVM significantly decreased associated with an increase in left ventricular fractional shortening and mean systolic and diastolic posterior wall velocity at 6 and 12 months of treatment. Positive correlations between PIIIP and LVM (r=0.49, p<0.005) and negative correlations between PIIIP and left ventricular fractional shortening (r=-0.31, p<0.05) were found. Delapril hydrochloride reduced PIIIP and LVM and improved cardiac function in hypertensive patients.     

Electrocardiographic changes in stroke patients without primary heart disease

OBJECTIVE: To examine the HIV seroconversion rate, risk factors for seroconversion, and changes in risk behavior over time in intravenous drug users (IVDU) in San Francisco, 1985-1990. DESIGN: Observational study. SETTING: All methadone maintenance and 21-day methadone detoxification programs in San Francisco. PARTICIPANTS: A total of 2351 heterosexual IVDU, of whom 681 were seronegative at first visit and seen at least twice ('repeaters'). MAIN OUTCOME MEASURES: HIV seroconversion rates, risk factors for seroconversion, and changes in behavior. RESULTS: The HIV seroconversion rate in repeaters was 1.9% per person-year (ppy) of follow-up [2.1% in women versus 1.7% in men (not significant); 4% in African Americans versus 1% in whites (P = 0.006); 3.9% ppy in the first third of the study, 1.2% in the second (P = 0.007), and 1.9% in the last (not significant)]. Risk factors for seroconversion were five or more sexual partners per year [hazard ratio (HR) = 2.6; P = 0.02], use of shooting gallery ever (HR = 2.9; P = 0.02), and less than 1 year (lifetime) in methadone maintenance (HR = 2.7; P = 0.02). Self-reported intravenous cocaine use fell from 33 to 15% over 5 years, shooting gallery use fell from 19 to 6%, and the proportion with five or more sexual partners fell from 25 to 10%. Bleach use rose to 75% of needle-sharers. CONCLUSIONS: The 1985-1990 HIV seroconversion rate in IVDU (1.9% ppy) was comparable to that in San Francisco cohorts of homosexual men (1.4% ppy). A decline in HIV seroconversion coincided with changes in risk behavior. Stable attendance of methadone maintenance was highly protective: the seroconversion rate in subjects with 1 year or more in methadone was 12% ppy.     

Relationship between left ventricular mass and serum cholesterol level in the untreated hypertensive

OBJECTIVE: To study the relationship between serum cholesterol level and left ventricular mass for a population of untreated hypertensive patients. DESIGN: A cross-sectional study. PATIENTS: We studied 273 untreated hypertensive patients without associated diseases consecutively referred for evaluation of blood pressure. All patients underwent M-mode echocardiographic assessment of left ventricular mass, office blood pressure measurement and 24 h ambulatory blood pressure monitoring. Fasting plasma glucose and total cholesterol levels were measured on the same day. RESULTS: We found a weak but significant correlation (r = 0.20-0.26, P < 0.01) between serum cholesterol level and left ventricular wall thickness or left ventricular mass irrespective of the mode of indexation used (height, height2.7 and body surface area). In multivariate analysis this relation remained significant after introduction of sex, age, weight, height, blood pressure and blood glucose level. When data for men and women were analysed separately the relationship between left ventricular mass and cholesterol remained significant for men only. CONCLUSION: There is a significant and independent positive relationship between serum cholesterol level and left ventricular mass that could contribute to the prognostic value of left ventricular hypertrophy.     

Left ventricular contractile performance, ventriculoarterial coupling, and left ventricular efficiency in hypertensive patients with left ventricular hypertrophy

Contractile performance of hypertrophied left ventricle may be depressed in arterial hypertension. Ventriculoarterial coupling is impaired when myocardial contractile performance is reduced and when afterload is increased. The left ventricular contractile performance and the ventriculoarterial coupling were evaluated in 30 hypertensive patients with moderate left ventricular hypertrophy and 20 control subjects. Left ventricular angiography coupled with the simultaneous recording of pressures with a micromanometer were used to determine end-systolic stress/volume index, the slope of end-systolic pressure-volume relationship, ie, end-systolic elastance, effective arterial elastance, external work, and pressure-volume area. In hypertensive patients, left ventricular contractile performance, as assessed by end-systolic elastance/ 100 g myocardial mass, was depressed (4.35 +/- 1.13 v 5.21 +/- 1.89 mm Hg/mL/100 g in control subjects P < .02), when end-systolic stress-to-volume ratio was comparable in the two groups (3.85 +/- 0.99 g/cm2/mL in hypertensive patients versus 3.51 +/- 0.77 g/cm2/mL in control subjects). Ventriculoarterial coupling, evaluated through effective arterial elastance/end-systolic elastance ratio, was slightly higher in hypertensive patients (0.53 +/- 0.08 v 0.48 +/- 0.09 mm Hg/mL in control subjects, P < .05), and work efficiency (external work/pressure-volume area) was similar in the two groups (0.78 +/- 0.04 mm Hg/mL in hypertensive patients versus 0.80 +/- 0.03 mm Hg/mL in control subjects). This study shows that despite a slight depression of left ventricular contractile performance, work efficiency is preserved and ventriculoarterial coupling is almost normal in hypertensive patients with left ventricular hypertrophy. Thus, it appears that left ventricular hypertrophy might be a useful means of preserving the match between left ventricle and arterial receptor with minimal energy cost.     

Left ventricular diastolic function in hypertensive patients with unstable angina and single coronary artery disease

The present study was performed to investigate left ventricular diastolic (LVD) function in hypertensive patients with unstable angina. Three groups of 17 patients each were studied. Group 1 consisted of hypertensives with unstable angina (HTU); group 2, normotensives with unstable angina (NTU); and group 3, untreated, uncomplicated hypertensives (HT). The LVD function was assessed echocardiographically by transmitral valve Doppler flow to measure the ratio between the early diastolic filling (E) and the atrial contraction phase (A). An E/A ratio of < 1 was suggestive of LVD dysfunction. Left ventricular mass (LVM), from an M-mode echocardiogram using the Penn-Cube formula, was corrected to body surface area (LVM/S) using a standard nomogram. Data are represented as median values and analyzed by Mann-Whitney test. P was significant at < .05. The HTU group had an E/A ratio of 0.8, and the NTU and HT groups had ratios of 1.17 and 1.1, respectively. There was significant diastolic dysfunction in the HTU group compared with the NTU and HT groups (P = .037 and .049, respectively). Although the LVM/S was significantly higher in the HTU group when compared with the HT group (110.6 and 96.9, respectively, P = .017), there was no significant difference between the HTU and NTU groups (123.1), P = .67. Hypertensive patients with unstable angina have significant LVD dysfunction that seems to be independent of LVM and ischemia. This may be attributable to increased stiffness of the left ventricle or structural left ventricular abnormalities.     

Heart rate and blood pressure variabilities in mild to moderate hypertensive patients with or without left ventricular hypertrophy

AIM OF THE STUDY: To compare heart rate (HR) and blood pressure (BP) variability in hypertensives with or without left ventricular hypertrophy (LVH). METHODS: Thirty-three mild to moderate hypertensive patients, mean age 45 +/- 15 years, underwent an echocardiogram, a 24 hr ambulatory BP monitoring (ABPM), a 24 hr ECG monitoring and a continuous BP recording over 15 minutes both in supine and standing positions, by using digital plethysmography (Finapres device). Statistical analysis: non parametric tests. RESULTS: [table: see text] CONCLUSION: LVH is associated with a reduction in the markers of sympathetic activity and a decreased baroreflex sensitivity.     

Effect of the treatment with amlodipine on left ventricular hypertrophy in hypertensive patients

BACKGROUND: Left ventricular hypertrophy (LVH) is one of the physiopathological effects of hypertension and one of the main risk factors for sudden death, myocardial infarction and congestive heart failure. Drugs to treat hypertension must not only reduce blood pressure, but also modify the facts which lead to ventricular hypertrophy. This study has been designed to assess the effect of amlodipine, a calcium-antagonist, on LVH in hypertensive patients. METHODS: 20 hypertensive patients (mild to moderate, both sexes, mean age 45.0 yr) were included in a single-blind study. After an initial, four weeks placebo period, active treatment was given (amlodipine 5 mg a day). Dose titration was made after 4-8 weeks to 10 mg a day if necessary and continued until the end of the study. Systolic (SBP) and diastolic blood pressure (DBP), as well as pulse rate (PR) and adverse events were recorded at every visit. Blood and urine analysis, catecholamine, plasmatic renin activity and Mode M echocardiography were made at the beginning and the end of the study. RESULTS: Only one patient was excluded. SBP and DBP showed a significantly fall (p < 0.001). In 80% of patients DBP fell under 90 mm Hg. Every echocardiographic parameter, but left ventricular diastolic dimension, showed significantly reductions at the end of the study: septum thickness (p = 0.001), posterior wall thickness (p = 0.001), left ventricular systolic dimension (p = 0.014), wall relative thickness (p = 0.015), shortening fraction (p = 0.009), left ventricular mass (p = 0.001) and corrected left ventricular mass (p = 0.001). Blood parameters did not modify. CONCLUSIONS: Amlodipine has a beneficial effect on LVH and also is an effective and safe drug to treat mild to moderate hypertension.     

Relationships between left ventricular mass, left ventricular work and coronary artery size in aortic regurgitation--possible mechanism of myocardial ischemia

To investigate the relationships between coronary artery size, left ventricular (LV) mass, and LV stroke work in aortic regurgitation (AR), these values were measured in 19 patients with severe AR. Twenty normal subjects and 15 patients with mitral regurgitation (MR) were used as control groups. The coronary area index, i.e., the coronary cross-sectional area divided by body surface area (BSA), was larger in the AR group than in the control groups in all measured sites except for the peripheral left anterior descending coronary artery (LAD) and right coronary artery (RCA). However, the coronary area index divided by the LV mass was significantly smaller in AR and MR patients than in normal subjects. Furthermore, the coronary area index divided by LV stroke work was smaller in AR patients than in MR patients and normal subjects. These results suggest that the coronary blood flow associated with the increased LV mass and stroke work caused by regurgitation was insufficient in patients with severe AR, especially in the area of the LAD. Therefore, the occurrence of myocardial ischemia in patients with severe AR may involve inadequate enlargement of the coronary artery which perfuses the LV, in addition to factors such as decreased coronary perfusion pressure, increased coronary artery resistance and decreased coronary flow reserve.     

Two-year follow-up study to evaluate the reduction of left ventricular mass and diastolic function in mild to moderate diastolic hypertensive patients

OBJECTIVE: To compare the effects of two antihypertensive agents, amlodipine and lisinopril, on left ventricular mass and diastolic filling in patients from primary care centers with mild to moderate diastolic hypertension. STUDY DESIGN: A second-year, open follow-up of a prospective, double-blind, randomized, parallel group, comparative study. METHODS: Male and female patients between 25 and 75 years-of-age with elevated diastolic blood pressure (four measurements > or = 95 mmHg from multiple measurements taken on three occasions and average diastolic blood pressure < 115 mmHg) were recruited from a population survey. After 4 weeks' placebo run-in, 71 patients were included of whom 60 finished the first study year and 51 finished the second study year. Patients were randomly assigned to receive doses of 5-10 mg amlodipine or 10-20 mg lisinopril, which were titrated on the basis of the effects on blood pressure. Primary endpoints were left ventricular mass index (LVMI) and early to atrial peak filling velocity. Office and ambulatory blood pressure were considered secondary endpoints. RESULTS: The decrease in blood pressure was equal for both treatment regimens in the first year. A statistically significant (P< 0.001) decrease in LVMI in both treatment groups was observed in the first year [-11.0 g/m2 (95% Cl -6.0 to -16.1) in the amlodipine group and -12.6 g/m2 (95% Cl -8.2 to -17.0) in the lisinopril group]. Early to atrial peak filling velocity did not change significantly within the treatment groups in the first year [+0.07 (95% CI -0.01 to +0.15) in the amlodipine group and +0.01 (95%9 Cl -0.06 to +0.08) in the lisinopril group. Blood pressure, LVMI and early to atrial peak filling velocity did not change in the second year of treatment. No significant differences in primary and secondary endpoints between treatment groups were found in the first or second year. Conclusion: The effects of amlodipine and lisinopril on left ventricular mass and early to atrial filling peak velocity after 2 years of treatment were similar and these effects were already observed after 1 year of treatment. Additional studies of longer duration (> or = 4 years) and with a larger sample size are recommended.     

Atherosclerosis and left ventricular hypertrophy: persisting problems in treated hypertensive patients

OBJECTIVES: First, to determine whether hypertensive patients managed in general practice have more advanced atherosclerosis and left ventricular hypertrophy than matched normotensive patients from the same practices. Second, to investigate the associations of several potentially modifiable factors with these vascular and cardiac outcomes. DESIGN AND METHODS: We performed a case-control study of 500 hypertensive cases (systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg or receiving treatment) and 506 age- (mean 61 years) and sex- (54% female) matched normotensive controls recruited from general practices. Carotid artery far wall thickness (CWT), assessed by B-mode ultrasound, and left ventricular mass (LVM), assessed by M-mode echocardiography, were the main study outcome measures. RESULTS: Mean systolic/diastolic blood pressure levels in the 399 treated cases (145/87 mmHg) were lower than those in untreated cases (158/94 mmHg) but higher than those in controls (133/82 mmHg, all P < 0.0001). Mean body mass index (BMI) and total triglyceride levels were higher and high-density lipoprotein cholesterol was lower in cases than in controls (all P < 0.0004). Mean CWT was 10% greater in cases than in controls and LVM was 14% greater (both P < 0.001), but both were similar in treated and untreated cases (P > 0.05). In multivariate analyses, blood pressure and BMI were both directly and independently related to CWT and LVM (both P < 0.0001). CONCLUSIONS: In this study, hypertensive patients managed in general practice - whether treated with antihypertensive drugs or not - had more advanced atherosclerosis and left ventricular hypertrophy than did matched normotensive patients. Efforts to lower blood pressure further and to reduce BMI could potentially reduce these differences, and this might lead to a reduction in the risk of major cardiovascular events.     

Electrocardiographic patterns relative to initiating mechanisms of exercise-induced ventricular tachycardia

The initiating mechanisms of exercise-induced ventricular tachycardia were studied in a population of 5842 patients who performed 9064 bicycle exercise tests. Sixty (1%) patients had 194 episodes of ventricular tachycardia during the test. Forty-two percent of these occurred during exercise and 58% during recovery. Two different initiating electrocardiographic patterns were observed. In 17 (28%) patients ventricular tachycardia was initiated by a short-long-short sequence of R-R intervals (group 1). Thirty-eight (63%) patients did not have this pattern of interval changes preceding ventricular tachycardia (group 2). Five (8%) other patients showed both patterns. The clinical characteristics of the groups were different for angina and cardiomyopathy but not for previous myocardial infarction. In group 1 ventricular tachycardia was related to recovery (76%; p < 0.05). In group 2 tachycardia occurrence was equally divided between exercise and recovery. The electrocardiographic differences suggest that different initiating mechanisms are involved in the development of exercise-induced ventricular tachycardia. The present findings may enhance aimed drug therapy in ventricular tachycardia.     

Reduced epicardial coronary vasodilator capacity in patients with left ventricular hypertrophy

BACKGROUND: Enlargement of the epicardial coronary arteries occurs in left ventricular (LV) hypertrophy as an adaptation to the increased coronary blood flow. METHODS AND RESULTS: Vasodilator capacity of the epicardial coronary arteries was determined in 44 patients. The dose-response relation of intracoronary nitroglycerin was assessed in 14 patients (7 control subjects and 7 patients with aortic stenosis [study A]) using quantitative coronary angiography. In a second study (B), vasodilator capacity of the epicardial coronary arteries was determined in 15 control subjects and 15 patients with valvular heart disease. In study A, a curvilinear dose-response relation with maximal vasodilation after 90 micrograms intracoronary nitroglycerin was found in both control subjects and patients with aortic stenosis. Vasodilator capacity was reduced in those with aortic stenosis, although sensitivity to nitroglycerin was similar in both groups. In study B, coronary circumferential length at baseline was larger in those with LV hypertrophy (12.2 +/- 2.2 mm) than in control subjects (8.6 +/- 1.5 mm; P < .001); after 100 micrograms intracoronary nitroglycerin, it increased to 12.9 +/- 2.2 mm (6 +/- 5%) in those with LV hypertrophy and to 10.3 +/- 1.5 mm (21 +/- 8%; P < .001) in control subjects. An inverse relation between baseline circumferential length and its percent increase after nitroglycerin was found (r = -.71, P < .001). CONCLUSIONS: Vasodilator capacity of the epicardial coronary arteries is reduced in patients with LV hypertrophy, although sensitivity to nitroglycerin is normal. This may be due to a flow-mediated decrease in coronary vasomotor tone and/or the occurrence of vascular remodeling with an enlargement of the coronary arteries.     

The cost and cardioprotective effects of enalapril in hypertensive patients with left ventricular dysfunction

This study examined the effect of enalapril on survival, resource use, and cost of care in patients with left ventricular dysfunction and hypertension using a retrospective analysis of patients who participated in the Studies of Left Ventricular Dysfunction (SOLVD). Among the 6797 SOLVD participants, 1917 patients had either elevated systolic (> or = 140 mm Hg) or diastolic (> or = 90 mm Hg) blood pressure. Therapy with enalapril was associated with a significant relative risk reduction for mortality (RR = 0.819, 95% CI: 0.68 to 0.98; P = .03). This resulted in a gain of 0.11 years (95% CI: 0.00 to 0.20 years) of survival during the average 2.8 year follow-up for this subgroup and was projected to result in a gain of 2.14 years (95% CI: 0.05 to 4.21 years) during the patient's lifetime. Enalapril significantly reduced the risk of first hospitalization for heart failure by 37%. For all types of hospitalizations, there was an average reduction of 32 hospitalizations per 100 patients treated with enalapril during the trial period (95% CI: 11.8 to 52.2 hospitalizations avoided per 100 patients), resulting in an estimated net savings of $1656 per patient during the trial period (95% CI: increased cost of $191 to savings of $3502). Although the projected lifetime net savings of $1456 was not significant (95% CI: increased cost of $9243 to saving of $12,527), evaluation of the cost per life year saved indicated that enalapril represented a cost-effective strategy. The estimated clinical benefit of enalapril among the hypertensive subgroup in SOLVD supports the recommendation that angiotensin converting enzyme (ACE) inhibitors should be considered as first line pharmacologic therapy for hypertensive patients with left ventricular dysfunction. From both the clinical and economic viewpoints, ACE inhibitors provide important clinical benefits and are cost-effective.     

Effects of ergotamine on myocardial blood flow in migraineurs without evidence of atherosclerotic coronary artery disease

The effects of intravenous ergotamine (0.25 mg) on basal and hyperemic (dipyridamole) myocardial blood flow (MBF), measured with positron emission tomography and H2(15)O, were assessed in 15 migraineurs in a double-blind, randomized, placebo controlled, crossover study. Ergotamine produced a 27% reduction in hyperemic MBF (2.62 +/- 0.11 vs 3.72 +/- 1.05 ml x min(-1) x g(-1); p <0.05), a 31% reduction in the coronary vasodilator reserve (1.81 +/- 0.50 vs 2.71 +/- 1.15; p <0.01), and a 55% increase in minimal coronary resistance (42.2 +/- 15 vs 26.7 +/- 8 mm Hg x min x ml(-1) x g(-1); p <0.001), suggesting vasoconstriction of the coronary microcirculation.     

Determinants of left ventricular mass in early hypertension

Four modified cyclic hexapeptides, tenuecyclamides A-D (1-4), were isolated along with the known antibiotic, borophycin (5), from the methanol extract of Nostoc spongiaeforme var. tenue (TAU strain IL-184-6). The planar structure of tenuecyclamides A-D (1-4) was determined by homonuclear and inverse-heteronuclear 2D-NMR techniques as well as by high-resolution mass spectrometry measurements. The absolute configuration of the asymmetric centers was studied by Marfey's method for HPLC. The stereochemistry of the asymmetric centers in tenuecyclamides A and B (1 and 2) could not be fully determined, while that of tenuecyclamides C and D (3 and 4) was unambiguously determined.     

123I-MIBG myocardial imaging in hypertensive patients: abnormality progresses with left ventricular hypertrophy

An active component of the sex pheromone system of the yellowish elongate chafer, Heptophylla picea was identified by GC-EAD. Mass spectral data and hydrogenation revealed that the active compound was a hexadecadien-4-olide. It was not possible to determine the double bond positions by direct DMDS derivatization of the pheromone, but partial hydrogenation (diimide) followed by DMDS derivatization showed that the double bonds were located in positions 7 and 15. FTIR (tracer) of the pheromone corroborated the lactone structure (1772 cm-1) and showed a band characteristic of a terminal double bond at 3073 cm-1, and one of a double bond in the cis-configuration at 3002 cm-1. Chiral resolution of the pheromone, after hydrogenation, demonstrated that the natural lactone had the (R)-stereochemistry. Synthetic (R,Z)-7,15-hexadecadien-4-olide, prepared from L-malic acid in 14 steps, was identical to the natural product in MS, IR, retention times and biological activity. This is the first fatty acid derivative compound found as a sex pheromone of a Melolonthinae species and as far as biosynthesis is concerned this is the most complex pheromone constituent of a scarab species.