Associazione indipendente tra la riserva di flusso coronarico e le pressioni di riempimento e il rilasciamento del ventricolo sinistro

Background: A cross-talk between coronary flow and left ventricular (LV) function is recognized. This study tested the hypothesis that impairment of coronary flow reserve (CFR) in arterial hypertension is associated with LV systolic and diastolic dysfunction, independently on abnormalities of LV geometry. Methods: We studied 59 newly diagnosed, never treated hypertensive patients, using transthoracic Doppler echocardiography, including pulsed Tissue Doppler of mitral annulus and CFR on left anterior descending artery (low dose dipyridamole). The study population was divided in 2 groups according to age-normalized relative wall thickness (RWTn): 36 with normal LV geometry (RWTn ≤ 0.41) and.23 patients with LV concentric geometry (RWTn > 0.41) Results: Patients with LV concentric geometry (RWTn > 0.41) had significantly lower midwall (but not endocardial) shortening, longer isovolumic relaxation time (IVRT), lower Tissue Doppler derived early diastolic velocity (Em), higher ratio of transmitral E velocity to Em and lower CFR than patients with normal LV geometry (RWTn ≤ 0.41). In the whole population lower CFR was significantly associated with lower midwall shortening and Em, longer IVRT and higher E/Em ratio. After controlling for heart rate, mean blood pressure and RWTn, only the relation of CFR with IVRT, Em and E/Em ratio remained significant. Conclusions: Reduced midwall mechanics is associated to lower CFR, a relation depending on LV concentric geometry. A reduced CFR is associated with both impaired relaxation and increased filling pressure, a relation that is independent on LV geometry and pressure load

Transthoracic coronary flow reserve and dobutamine derived myocardial function: a 6-month evaluation after successful coronary angioplasty

After percutaneous transluminal coronary angioplasty (PTCA), stress-echocardiography and gated single photon emission computerized tomography (g-SPECT) are usually performed but both tools have technical limitations. The present study evaluated results of PTCA of left anterior descending artery (LAD) six months after PTCA, by combining transthoracic Doppler coronary flow reserve (CFR) and color Tissue Doppler (C-TD) dobutamine stress. Six months after PTCA of LAD, 24 men, free of angiographic evidence of restenosis, underwent standard Doppler-echocardiography, transthoracic CFR of distal LAD (hyperemic to basal diastolic coronary flow ratio) and C-TD at rest and during dobutamine stress to quantify myocardial systolic (S(m)) and diastolic (E(m )and A(m), E(m)/A(m )ratio) peak velocities in middle posterior septum. Patients with myocardial infarction, coronary stenosis of non-LAD territory and heart failure were excluded. According to dipyridamole g-SPECT, 13 patients had normal perfusion and 11 with perfusion defects. The 2 groups were comparable for age, wall motion score index (WMSI) and C-TD at rest. However, patients with perfusion defects had lower CFR (2.11 ± 0.4 versus 2.87 ± 0.6, p < 0.002) and septal S(m )at high-dose dobutamine (p < 0.01), with higher WMSI (p < 0.05) and stress-echo positivity of LAD territory in 5/11 patients. In the overall population, CFR was related negatively to high-dobutamine WMSI (r = -0.50, p < 0.01) and positively to high-dobutamine S(m )of middle septum (r = 0.55, p < 0.005). In conclusion, even in absence of epicardial coronary restenosis, stress perfusion imaging reflects a physiologic impairment in coronary microcirculation function whose magnitude is associated with the degree of regional functional impairment detectable by C-TD

Echocardiography in patients with hypertrophic cardiomyopathy: usefulness of old and new techniques in the diagnosis and pathophysiological assessment

Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiomyopathy. The identification of patients with HCM is sometimes still a challenge. Moreover, the pathophysiology of the disease is complex because of left ventricular hyper-contractile state, diastolic dysfunction, ischemia and obstruction which can be coexistent in the same patient. In this review, we discuss the current and emerging echocardiographic methodology that can help physicians in the correct diagnostic and pathophysiological assessment of patients with HCM

Coronary flow reserve and myocardial diastolic dysfunction in arterial hypertension

The aim of this study was to assess the relation between coronary blood flow and left ventricular (LV) myocardial diastolic dysfunction in arterial hypertension. The study population included 30 hypertensive patients who were free of coronary artery disease and pharmacologic therapies. They underwent standard Doppler echocardiography and color tissue Doppler of the middle posterior septum at baseline and with high-dose dobutamine, and second-harmonic Doppler flow analysis of the distal left anterior descending coronary artery at baseline and after vasodilation by dipyridamole (0.56 mg/kg IV in 4'). Coronary flow reserve (CFR) was estimated as the ratio of hyperemic and baseline diastolic flow velocities. According to CFR, hypertensives were divided into 2 groups: 15 patients with normal CFR (>/=2) and 15 patients with reduced CFR (<2). The 2 groups were comparable for sex, age, body mass index, baseline heart rate, and blood pressure. LV mass index was greater in hypertensives with reduced CFR (p <0.01). By color tissue Doppler, baseline and high-dose dobutamine septal systolic velocities did not differ between the 2 groups. The ratio between myocardial velocities in early diastole and at atrial contraction (E(m)/A(m) ratio) was lower in patients with reduced CFR, both at baseline (p <0.05) and with high-dose dobutamine (p <0.00001). After adjusting for age, body mass index, LV mass index, and both high-dose dobutamine diastolic blood rate and heart rate by a multiple linear regression analysis, E(m)/A(m) ratio at high-dose dobutamine was independently associated with CFR in the overall population (beta 0.62, p <0.0005) (cumulative R(2) 0.38, p <0.0005). In conclusion, this study provides evidence of an independent association between CFR and myocardial diastolic function. In hypertensive patients without coronary artery stenosis, CFR alteration may be a determinant of myocardial diastolic dysfunction or diastolic impairment that should be taken into account as possibly contributing to coronary flow reduction

[Real-time multiplane echocardiography. Current applications, limits and perspectives]

Echocardiography is the most commonly used imaging technique in current clinical cardiology practice and is usually performed using a monoplane approach. In recent years new matrix-array transducers have become available that allow the real-time simultaneous display of two or more echocardiographic scanning planes from the same acoustic window. This multiplane approach is particularly interesting as it may reduce, during the examination, the number of probe movements and consequently facilitate image acquisition. In some clinical applications, moreover, the multiplane approach improves both accuracy and reproducibility of echocardiography. This review evaluates the state of the art of multiplane echocardiography and discusses possible clinical applications, advantages and limitations of this technique