Severe degenerative aortic stenosis: when a senile patient is a candidate for surgery.

Senile aortic stenosis is characterized by calcific degeneration of the valve that prevents the full opening of the cusps in systole. The disease may be silent for many years despite the presence of severe flow obstruction and generally is associated with aortic regurgitation and calcification of the coronary arteries. The continuous increase of the aged population with aortic stenosis entails difficult decisions in selecting the candidates for aortic valve replacement in order to optimize the timing for surgery. Although clinical examination is still fundamental for the diagnosis of the disease and the screening of the population, noninvasive assessment by Doppler echocardiography has transformed the management of these patients. The procedure allows better identification of patients who may benefit from valve replacement in particular in the setting of a ''low output/low gradient'' state and permits a follow-up of the progression of the disease in patients who are not yet candidates for surgery. It also allows a decrease in the utilization of invasive hemodynamics becoming a cost benefit tool for the health system. When performed properly, it is relatively time consuming, needs experience but offers major anatomic and hemodynamic data. Under these circumstances, cardiac catheterization is required only in cases when there is discordance between the clinical assessment and cardiac ultrasound evaluation. In this review we summarize the prevalence and significance of the disease in the elderly population and the use of all recent echocardiographic data that may help select the true candidates for surgery.

Contrast enhanced imaging of left internal mammary artery after vasodilation improves the evaluation of the bypass graft.

AIM: The aim of the study is to evaluate patency and flow reserve by echocardiography in arterial grafts using the left internal mammary artery (LIMA) to the left anterior descending coronary artery (DA). The main limitations in performing this study routinely are the weakness of the Doppler signal and the exact chest localization of the graft. The purposes of the study were: to verify the feasibility of the echo color Doppler method on LIMA; to verify which between the parasternal or supralavicular view is the better approach to obtain a clear signal; to verify the increase of systolic and diastolic flow velocity of LIMA in basal conditions and after infusion of dipyridamole, and if the visualization of the Doppler signal improves after contrast infusion. METHODS: Twenty patients (all males, mean age 63+/-7.8 years) with previous coronary artery bypass in the last 10 years, and without any significant stenosis in the left mammary artery graft as proved by a recent coronary angiogram (within 6 months), were selected for our study. LIMA was evaluated by two echocardiographic approaches. Patients were studied at rest and after pharmacological infusion of dipyridamole using the protocol of 0.56 mg/kg in 4 minutes. Contrast enhancement was infused in order to improve the Doppler signal using Levovist contrast agent at rest and after vasodilatation. Diastolic and systolic peak flow velocities, their ratio and the diastolic and total velocity time integrals were evaluated. RESULTS: The results showed that using the supraclavicular approach we obtained the visualization of the graft at rest in all patients (100%) and using the parasternal approach in 19 out of 20 (95%) even without contrast injection. At rest, the diastolic and systolic peak flow velocities were 0.417+/-0.133 m/s and 0.368+/-0.1291 m/s; their ratio (diastolic/systolic) was 0.882+/-0.7362. The overall and diastolic velocity time integrals were 0.1571+/-0.0645 m and 0.2232+/- 0.0701 m. After dipyridamole infusion we observed in all patients an increase in diastolic and systolic peak flow velocities as expected by 0.582+/-0.342 m/s (p<0.005) and 0.73+/-0.427 m/s (p<0.005). Contrast injection at rest and after peak dipyridamole infusion showed a better and clearer Doppler signal of the graft allowing an easier evaluation of the velocity curves in all patients. In fact using the association dipyridamole-Levovist the velocity ratio and the total and diastolic velocity time integral values were 1.268+/-0.368 (p<0.05), 0.3492+/-0.131 m (p<0.05) and 0.2309+/-0.153 m (p<0.05). CONCLUSION: In conclusion, this new echo-color-Doppler approach seems to be valid for the evaluation of the patency rate and flow reserve of the internal mammary artery graft, and helps to better select patients who really need angiography.

When should asymptomatic patients with combined severe aortic stenosis and aortic insufficiency undergo valve replacement? A clinical case.

Indications to prosthetic aortic valve implantation in patients with aortic stenosis or aortic regurgitation or both stenotic or regurgitant aortic valve, who present without symptoms, are controversial. We present the case of an asymptomatic patient with combined severe aortic stenosis and an equally important insufficiency, undergoing surgery for valve substitution with a bileaflet prosthesis. After surgery he was treated with warfarin according to the doses recommended and underwent follow-up with clinical and echocardiographic exams. Eight months after intervention the patient had an embolic stroke with aphasia and right hemiplegia, despite the therapeutic level of INR. At present, even though he has partly recovered motor function, he reports a noteworthy decline in life quality, because of the persistent speech difficulties. We use this case as the starting point for a discussion of the chance of referring patients affected by aortic valvulopathy to valve substitution, in the absence of symptoms.

Cardiopulmonary exercise testing and exhaled nitric oxide in the assessment of patients with mitral stenosis.

AIM: In patients with mitral stenosis, symptoms do not always correlate with echocardiographic data. The aims of the study were to evaluate the role of cardiopulmonary exercise testing in the assessment of patients with mitral stenosis and to quantify nitric oxide production at rest and at the end of exercise. METHODS: We evaluated 43 patients with moderate to severe mitral stenosis with a discrepancy between echocardiographic data and symptoms. Nitric oxide output was calculated by measuring nitric oxide concentration in the exhaled air at rest and at the end of exercise test. RESULTS: Patients were divided in 2 groups: group 1 with a functional capacity <75% at cardiopulmonary exercise test (VO2max in % of the predicted one) and group 2 with functional capacity >75%. Transvalvular gradient and pulmonary artery pressure were significantly higher in group 1 than in group 2 (respectively 9.07 +/- 2.11 mmHg vs 6.01 +/- 1.08 mmHg, p<0.001 and 42.8 +/- 7.2 mmHg vs 33.1 +/- 4.7 mmHg, p<0.001). Patients of group 1 had a lower nitric oxide output at the end of exercise compared to group 2 (231.4 +/- 96.6 nl/min vs 326.3 +/- 74.0 ml/min, p=0.01) and to normal subjects (511.15 +/- 180.1 nl/min, p<0.001). CONCLUSION: Cardiopulmonary exercise testing provides objective non invasive information in the evaluation of patients with discrepancy between symptoms and echocardiographic data. Different levels of nitric oxide output during exercise suggest the role of nitric oxide in regulating pulmonary vascular tone.

Sonovue improves endocardial border detection and variability in assessing wall motion score and ejection fraction during stress echocardiography.

BACKGROUND: Stress echocardiography is useful for assessing patients with coronary artery disease unable to undergo formal exercise testing. Considerable skill is required to avoid large intra- and inter-observer variability due to poor endocardial definition. Intravenous ultrasound contrast agents are now available which may improve this variability. AIM: To study intravenous Sonovue in assessing wall motion score and ejection fraction (EF) during stress echocardiography. METHODS: Thirty-eight patients undergoing arbutamine stress echocardiography for known or suspected coronary artery disease were studied. Echocardiographic analysis of wall motion score index, endocardial border detection (EBD) and EF was performed at rest and at peak stress before and after intravenous injection of Sonovue, by experienced and inexperienced observers. RESULTS: All three observers noted an improvement in endocardial border definition following Sonovue (p=<0.001). At baseline, there was a significant difference in wall motion score index between experienced and inexperienced observers at rest (p=0.01) and at peak stress (p=0.001). Following Sonovue administration this was no longer significant (p=0.07, p=0.114). Intra-observer variability of end diastolic, end systolic volumes (ESV) and EF improved following contrast (p<0.05) at rest and during stress. CONCLUSION: Sonovue significantly improved EBD and reduced intra-observer variability of EF at rest and during peak arbutamine infusion.