The haemodynamic cascade

In this issue of the Netherlands Heart Journal, Jansen et al. describe the influence stress echocardiography has on clinical decision-making in patients with mitral valve disease [1]. In 1935, Tenant and Wiggers described the sequelae of coronary occlusion [2]. From their description the ischaemic cascade has been derived. In this cascade, symptoms are a relatively late phenomenon and are preceded by electrocardiographic changes. This has led to the routine application of stress electrocardiog-raphy in the evaluation of patients with suspected coronary artery disease. In patients with valvular heart disease one could assume the existence of a haemodynamic cascade. In the haemodynamic cascade, which starts with seemly insignificant valve defects, the second phase would be haemodynamic changes, followed by cardiac adaptation and as the last phase, symptoms. Analogous to stress electrocardiography, stress echocardiography can then be applied to relate symptoms with echocardiographic findings. Stress in patients with mitral valve regurgitation may provoke an increase of the right ventricular systolic pressure (RVSP) as the increase of heart rate leads to an increase in regurgitant volume per unit of time. In case of mitral valve stenosis, acceleration of the heart rhythm leads to a decreased atrial emptying time resulting in an intra-atrial pressure rise and hence a rise in RVSP. Nowadays, RVSP can be determined non-invasively using conventional Doppler echocardi-ography. The problem in the clinical management of patients with valvular heart disease is that their symptoms might be caused by physical conditions other than their valvular heart disease, such as obesity and diastolic dysfunction to mention a few. A discrepancy may exist between the presenting complaints and the echocardiographic findings. The application of stress allows one to correlate symptoms with the intensity of stress and the corresponding haemodynamic changes. According to the haemodynamic cascade, guidelines based on symptoms are obsolete. Guidelines based on dimensions are still used but in the era that valve function can be determined non-invasively by Doppler echocardiography, guidelines should better be based on the haemodynamic consequences of valvular heart disease. Theoretically, it should be possible to derive a heart rate/ RSVP index in which the denominator is determined by guidelines and the numerator by the heart rate. The value of this index easily determines whether an operation has to be performed or not. For instance: the denominator is now 60 mmHg, (guidelines). If this value has been reached during stress with a heart rate of 120 beats/min, the value …