**2. Echocardiography in aortic stenosis patients**

Echocardiography is the key diagnostic tool, not only to confirm the presence of AS, but also to assesses the degree of valve calcification, LV function and wall thickness. Today, echocardiography provides prognostic information in patients with AS.

The severity of AS is provided with a very high sensitivity and specificity by Doppler echocardiography. A valve area 1.0 cm2 in a patient with AS is considered severe. The indexing of aortic valve area to body surface area is more powerful parameter, and a cut-off value of 0.6 cm2/m2 is considered severe AS. However, valve area detected by Doppler

Echocardiography in Severe Aortic Stenosis 27

Aortic stenosis is a chronic progressive disease. Patients with AS may remain asymptomatic for a long period of time, and the duration of the asymptomatic phase varies widely among individuals. The most frequent cause of death in symptomatic patients is sudden cardiac death. However, sudden cardiac death in asymptomatic

Older age, presence of atherosclerotic risk factors, valve calcification, peak aortic jet velocity, low LV EF and increase of transvalvular pressure gradient with exercise, were shown as

The development of symptoms on exercise testing, in physically active patients with AS, predicts a very high likelihood of symptom development within 12 months. The occurrence of symptoms, in these patientsş is a correlate of poor prognosis. The increased of mortality in these patients has been reported within months of symptom onset, which is often not

**4. Echocardiographic predictors in patients with severe aortic stenosis and** 

Left ventricular systolic function was shown as one of more important predictors of patients with AS. Patients with AS and LV systolic dysfunction have a poor prognosis if valve replacement is not performed. LV EF, as the most important conventional parameter for the LV global systolic function, was consistently reported as a postoperative prognostic factor in patients with severe AS. Patients with severe left ventricular dysfunction have increased intra-operative mortality, and there are yet contradictions about their improved outcomes after the AVR. Generally, the LV systolic dysfunction is not a contraindication to surgery. It was shown that patients who underwent AVR have a 5-year survival rate 60–70%, with a high operative mortality in the range of 10–15% for patients with LV systolic dysfunction. To predict the postoperative outcome of patients with severe AS and impaired LV function, the preoperative dobutamine stress echocardiography is useful technique. The presence of good contractile reserve in dobutamine stress echocardiography supports potential benefit

AVR decreases the LV afterload, through transvalvular pressure drop (Figure 2), resulting

LV mass regression predominantly occurs within the first 6 months of surgery. Even there are few publications regarding the pre-operative echocardiographic predictors of LV functional recovery in AS patients with low EF, it justify the statement to consider these patients for the operation, after individual assessment of the patient, considering co

Recovery of LV function was evident after aortic valve replacement in the majority of

Patients with increased LV end-systolic dimension and/or LV systolic volume index seem to have less chance for the LV functional recovery. It seems that these patients loosed

**3. Outcome of patients with aortic stenosis** 

independent predictors of poor outcome in AS patients.

patients with AS is very rare.

promptly reported by patients.

**poor left ventricular systolic function** 

from AVR and better outcome in these patients.

patients with aortic stenosis and pre-operative LV dysfunction.

in regression of LV hypertrophy.

morbidities and general conditions.

echocardiography cannot be the only parameter for clinical decision making for aortic valve replacement, and it should be considered in combination with flow rate, pressure gradient and ventricular function, as well as functional status of an individual patient.

In patients with AS and normal left ventricular (LV) ejection fraction (EF) the mean pressure gradient of 50 mmHg (Figure 1), was used as a cut-off for the decision making for aortic valve replacement. However, in patients with depressed global LV function, even in patients with severe AS, Doppler echocardiography may result with low pressure gradients (underestimated gradients). In these patients, stress echocardiography using low-dose dobutamine may be helpful to distinguish truly severe AS patients from the rare cases of pseudosevere AS. In patients with truly severe AS, only small changes in valve area, but significant increase in pressure gradients are shown, whereas in pseudosevere AS patients are registered significant increase of valve area surface, but only minor changes in pressure gradients, before and at peak dose of dobutamine. The dobutamine stress-echocardiography is useful also to detect the presence of contractile reserve, which has prognostic implications.

Fig. 1. Continues Doppler velocity of the aortic valve, in a patient with high pressure gradient and normal EF, before aortic valve replacement.

echocardiography cannot be the only parameter for clinical decision making for aortic valve replacement, and it should be considered in combination with flow rate, pressure gradient

In patients with AS and normal left ventricular (LV) ejection fraction (EF) the mean pressure gradient of 50 mmHg (Figure 1), was used as a cut-off for the decision making for aortic valve replacement. However, in patients with depressed global LV function, even in patients with severe AS, Doppler echocardiography may result with low pressure gradients (underestimated gradients). In these patients, stress echocardiography using low-dose dobutamine may be helpful to distinguish truly severe AS patients from the rare cases of pseudosevere AS. In patients with truly severe AS, only small changes in valve area, but significant increase in pressure gradients are shown, whereas in pseudosevere AS patients are registered significant increase of valve area surface, but only minor changes in pressure gradients, before and at peak dose of dobutamine. The dobutamine stress-echocardiography is useful also to detect the presence of contractile reserve, which

Fig. 1. Continues Doppler velocity of the aortic valve, in a patient with high pressure

gradient and normal EF, before aortic valve replacement.

and ventricular function, as well as functional status of an individual patient.

has prognostic implications.
