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Background: The usefulness of Doppler strain rate imaging for assessment of left ventricular regional diastolic function has not been fully determined. Objective: We aimed to clarify the relationships between diastolic strain rates and global diastolic function and find a useful index for regional diastolic function in patients with hypertrophic cardiomyopathy (HCM). Methods: Strain rate curves were obtained using an apical approach at 12 different sites of the left ventricular myocardium in 25 patients with HCM and 20 control subjects, and peak early diastolic strain rate (E"S"R), peak late diastolic strain rate, and the time from QRS to E"S"R were measured. The flow propagation velocity was measured using color M-mode Doppler echocardiography as a global diastolic index. Results: Each of the spatially averaged values of E"S"R and E"S"R/peak late diastolic strain rate and the coefficients of variation of time from QRS to E"S"R was significantly correlated with flow propagation velocity, but the best correlation was observed in E"S"R. Although both E"S"R and peak late diastolic strain rate of each myocardial segment of patients with HCM tended to decrease as the wall thickness increased, only E"S"R significantly decreased even in the segments without apparent hypertrophy. Conclusions: In patients with HCM, the reduction of E"S"R was more closely associated with global diastolic dysfunction than asynchrony, and E"S"R may be a useful and sensitive index for regional diastolic function.

Background: Myocardial viability is not synonymous with contractile reserve and identifiable in a significant percentage of dysfunctional myocardial segments without contractile reserve. The usefulness of ultrasonic tissue characterization by the phase-corrected magnitude of cyclic variation of integrated backscatter (MVIB) in chronic coronary artery disease is not fully validated. Thus, whether MVIB predominantly reflects the contractile reserve or myocardial viability of chronically dysfunctional myocardium was determined. Methods: The MVIB of severely dysfunctional interventricular septum or posterior wall was measured in 34 consecutive patients with previous myocardial infarction. Dobutamine stress echocardiography and fluorine-18 fluorodeoxyglucose positron emission tomography were used as the standards of contractile reserve and myocardial viability, respectively. Results: Among 44 dysfunctional segments, only 15 were judged as having contractile reserve and 29 were judged as not by dobutamine stress echocardiography, whereas 26 segments showed myocardial viability using fluorine-18 fluorodeoxyglucose positron emission tomography and 18 did not. MVIB was greater in segments with than in those without contractile reserve (4.7 +/- 2.2 vs -1.4 +/- 4.9 dB, P < .0001), but there was considerable overlap between the groups. On the other hand, MVIB of segments with and without myocardial viability (4.1 +/- 2.6 vs -4.3 +/- 3.3 dB, P < .0001) was distinctly different and predicted myocardial viability with a sensitivity of 92% and a specificity of 94%. Conclusions: For patients with chronic coronary artery disease, MVIB better reflects myocardial viability than it does contractile reserve. Ultrasonic tissue characterization, in concordance with fluorine-18 fluorodeoxyglucose positron emission tomography, is a sensitive method for detecting myocardial viability.

To examine the contribution of the renin-angiotensin system to hypertrophic cardiomyopathy (HCM), we studied 96 patients with HCM (mean age 50 years, 55% male), 105 of their unaffected siblings and offspring, and 160 healthy subjects without known hypertension and left ventricular hypertrophy (LVH) who were frequency matched to cases by age and sex. Patients were divided into familial or sporadic HCM (FHCM or SHCM) groups with or without affected members of their family. The region of interest in the angiotensinogen (AGT) gene, the missense mutation with methione-to-threonine amino acid substitution at codon 235 in angiotensinogen (M235T), was amplified by polymerase chain reaction with the use of allele-specific oligonucleotide primers flanking the polymorphic region of the AGT gene to amplify template deoxyribonucleic acid prepared from peripheral leukocytes. The T allele frequency was higher in the SHCM group than in unaffected siblings and offspring (88% vs 78%, @g ^2= 4.6, p < 0.05). The M allele frequency was higher in unaffected siblings and offspring than in patients with SHCM (23% vs 12%, @g^2= 4.6, p < 0.05). The T allele frequency among unaffected siblings and offspring was similar to that observed in healthy subjects (78% vs 78%). We conclude that HCM, especially in sporadic cases, is partially determined by genetic disposition. The molecular variant of angiotensinogen T235 seems to be a predisposing factor for cardiac hypertrophy in HCM and carries an approximately twofold increased risk. (Am Heart J 1997;133:184-9.)

The concentrations of pollutants, especially polycyclic aromatic hydrocarbons (PAHs), originating from automobile emissions are high in areas around urban arterial roads. To investigate the possibility of using urinary 1­hydroxypyrene (1­POH), a metabolite of pyrene, as a marker for estimating the amount of human exposure to PAHs, both an animal experiment and an ecological correlation study were conducted. Rats were exposed to one of two sources of PAH: diesel engine emissions containing particulate matter and NO₂ at average concentrations of 4.20 mg/m3 and 2.90 ppm, respectively, or, for the control group, air having the respective average concentrations of 0.01 mg/m3 and 0.02 ppm. The concentration of pyrene was 36 ng/mg in the particulate matter in the diluted diesel engine exhaust and 9.0 ng/g in the feed to the rats. Urinary 1­POH levels in the rats of the exposure group increased remarkably over those of the control group, 2.4 times as much by the 2nd week of exposure and 5.6 times by the 4th and 8th weeks. The ecological correlation study was conducted in 1988 and 1989 in two areas of Tokyo along arterial roads (Meguro and Itabashi Wards) and in one suburban area (Higashiyamato City) to measure urinary 1­POH levels in elementary school children who lived in those areas. Urinary samples were collected in October in 1988, as well as in January, May, and July in 1989. Throughout the period of investigation, the schoolchildren in the highly NOx­polluted Meguro and Itabashi Wards showed significantly higher urinary 1­POH levels than the children in the less­polluted Higashiyamato City by a factor of 1.1 ~ 1.6. These results suggest that the urinary 1­POH level could be used as a good marker for estimating the amount of exposure of residents to PAHs.Copyright 1993, 1999 Academic Press