[Doppler tissue imaging: a new method in the study of diastolic function in left ventricular hypertrophy]. / Il Doppler tissue imaging, nuova metodica di studio della funzione diastolica nell'ipertrofia del ventricolo sinistro.

BACKGROUND: Many factors influence diastolic function indexes obtained by monitoring left ventricular filling. Recent reports suggest that the study of myocardial wall velocity with Doppler tissue imaging (DTI) can give diastolic function parameters that are less affected by the same factors. An altered diastolic function has been demonstrated with invasive methods in patients with left ventricular hypertrophy (LVH). The aims of this study were 1) to compare a group of healthy subjects with a group of patients with LVH and presumably affected by diastolic dysfunction, to try to demonstrate if DTI could give new indexes to discriminate between the two groups; 2) to compare the indexes obtained with DTI against the ones given by Doppler study of left ventricular filling in the two populations. MATERIALS AND METHODS: Forty-two patients with LVH were compared to forty normal subjects. We studied the posterior wall velocity with pulsed DTI from parasternal view, measuring the early diastolic velocity (E'), the late diastolic velocity (A') and the E'/A' ratio. In addition, we estimated the usual ventricular filling parameters and the time interval between R wave of ECG and the peaks of E' and E waves. RESULTS: At left ventricular filling, patients with LVH showed an increase in A-wave peak velocity (mean 75.3 cm/s versus 66.4 cm/s; p < 0.05) and prolonged deceleration time (mean 216 ms versus 181 ms; p < 0.05), as compared to normal reference subjects. E-wave peak velocity and E/A ratio did not differ between the two groups. At DTI, patients with LVH had decreased early diastolic velocity (E') (mean 9 cm/s versus 12 cm/s; p < 0.05) and E'/A' ratio (mean 1.53 versus 1.91; p < 0.05) as compared to the control group. We observed an inverse correlation between E' wave and age in normal subjects. There was no correlation between the early diastolic myocardial velocity (E') and early inflow velocity (E) in both groups. A correlation was found between A and A' waves in normal subjects, but not in hypertrophic ones. The E'-wave peak always preceded the E-wave peak in all the subjects. CONCLUSION: Diastolic function indexes achieved by DTI can offer additional information that is independent of the data derived from left ventricular filling.

[Doppler tissue imaging in the study of the diastolic function in amyloidosis cardiopathy]. / Il Doppler tissue imaging nello studio della funzione diastolica nella cardiopatia amiloidosica.

Doppler tissue imaging (DTI) is an adaptation of the color-doppler, which allows the measurement of low-speed myocardial wall movement. We describe the case of a 51-year-old woman suffering from cardiac amyloidosis with serious endangerment of the diastolic function and mitral flow velocity pattern that was indistinguishable from the normal. The protodiastolic speed of the myocardial walls was measured with pulsed DTI, which was used as a diastolic function index. In this patient, the speed was 5 cm/sec, which was markedly lower than the values found in normal subjects and published recently. Moreover, the DTI M-mode images are examined here in order to point out different characteristics compared to the ones that can be obtained in normal subjects. This therefore exemplifies the possible use of this new technique in studying diastolic function.

Intracellular magnesium and inositol 1,4,5-trisphosphate receptor: molecular mechanisms of interaction, physiology and pharmacology.

This review focuses on the action of intracellular magnesium ion on the inositol 1,4,5-trisphosphate (IP3) receptor, the almost ubiquitous membrane-bound Ca2+ channel gated by the intracellular second messenger IP3. Experimental data have shown that Mg2+ is a non-competitive inhibitor of the IP3-gated Ca2+ channel and of [3H]-IP3 binding. The relevance of the Mg2+ effect is discussed in relation to: (a) the physiological role of the IP3-induced release of Ca2+ from intracellular Ca2+ stores, i.e., Ca2+ homeostasis of activated cells, in particular cardiac myocytes; (b) the modulation exerted by changes of [Mg2+]o and [Mg2+]i on basic cardiac functions, e.g., inotropism, chronotropism and automaticity; and (c) the pathogenesis of automatic arrhythmias, caused by either early or delayed afterdepolarizations, in which IP3-induced release of Ca2+ may be involved.

Hypertension, obesity and response to antihypertensive treatment: results of a community survey.

A random sample of 2,854 subjects aged 35-64 was examined in the town of Vicenza (Italy) as part of the 'Hypertension Management Audit Project'. Pearson's correlation coefficient and multivariate analysis considering systolic and diastolic blood pressure, age and body mass index (BMI) were performed. SBP was more closely correlated with age than DBP. BMI correlated with both SBP and DBP, but very little with age. Fifty-seven percent of the men had a BMI of 25.5 or more and 49% of the women had a BMI of 24.5 or more. The quality of BP control in the treated patients was worse in the overweight when compared with the lean patients, although overweight and lean patients are treated with the same frequency.

[The clinical and prognostic significance of the infarct size in patients discharged after a myocardial infarct]. / Significato clinico e prognostico dell'infarct size nei pazienti dimessi dopo infarto miocardico.

The authors report their experience in the determination of the infarct size (IS) by means of enzymatic analysis in a series of 281 consecutive patients (230 males, 51 females) admitted to the CCU because of myocardial infarction (MI), who did not benefit from thrombolytic therapy in the acute phase. To obtain the enzymatic IS, the serum activity of creatine kinase (CK) is determined every 4 hours for 48 hours and after 72 hours; Sobel's formula is used and results are expressed as CK-g-Eq of tissue. The enzymatic IS was compared to the degree of left ventricular dysfunction (assessed by echocardiography); to the electrocardiographic extension of necrosis; to the severity of ventricular arrhythmias (expressed as Lown's class) on 24-hour Holter monitoring; to cardiac mortality at 2 years. Mean estimated enzymatic IS of the population under study was 129 +/- 101 g-Eq. Patients with extensive MI (216 +/- 144 g-Eq) had significantly (p less than 0.05) higher IS compared to patients with inferior (131 +/- 93 g-Eq), anterior (105 +/- 65 g-Eq) and non-Q wave MI (73 +/- 54 g-Eq); also, a statistically significant difference (p less than 0.05) was found between inferior and non-Q wave MI. Patients with severely compromised left ventricular function (defined as an echocardiographic ejection fraction less than 30%), had significantly higher values of IS compared to patients with preserved left ventricular function (171 +/- 130 vs 120 +/- 93 g-Eq; p less than 0.05). A poor correlation was found between enzymatic IS and ventricular arrhythmias documented at pre-discharge 24-hour Holter monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)