[Usefulness of the Doppler index delta P/delta t in the evaluation of left ventricular systolic dysfunction].
OBJECTIVE
It has been shown that the delta P/delta t index, derived from the continuous Doppler mitral regurgitation signal correlates strongly with dP/dt. This study evaluates the feasibility, reproducibility and correlation of the index with ejection fraction and other conventional echocardiographic parameters.


METHODS
One hundred and ten patients with mitral regurgitation demonstrated by colour Doppler were studied. delta P/delta t were calculated by the ratio between the interval of pression between two points of the Doppler signal (-1 and -3 m/s; 32 mmHg, applying the modified Bernouilli equation) and the interval of time (s) which separates both. Ejection fraction was measured in 70 patients by non-echocardiographic methods (isotopic ventriculography, n = 52, and angiography, n = 18).


RESULTS
The index was feasible in 91 cases, the variability of intra and interobserver was 5% and 7% respectively. The correlation between delta P/delta t and ejection fraction was significant although weak (r = 0.59; p < 0.001; n = 70). It was better in the group of dilated idiopathic myocardiopathy (r = 0.72; p < 0.001; n = 18) than in the group of myocardial infarction (r = 0.54; p < 0.01; n = 25). No significant correlation was founded in the cases with mitral rheumatic valvulopathy. Regarding to the echocardiographic parameters, the best correlation was obtained with end systolic diameter (r = -0.64; p < 0.001; n = 49). Finally, a value of delta P/delta t < 1,000 mmHg/s predicted the existence of left ventricular systolic dysfunction with high accuracy (84%), sensitivity (80%) and specificity (92%).


CONCLUSIONS
High feasibility when mitral regurgitation exists, adequate reproducibility and heightened precision in diagnosing left ventricular systolic dysfunction, are characteristics which make delta P/delta t useful in the echocardiographic routine practice.
Alvarez López
M
M
Servicio de Cardiología, Hospital Virgen de las Nieves, Granada.
Alcalá López
J E
JE
Baún Mellado
O
O
Tercedor Sánchez
L
L
Ramírez Hernández
J A
JA
Rodríguez Padial
L
L
Azpitarte Almagro
J
J
D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000503:physiopathology; D003627:Data Interpretation, Statistical; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology; D015588:Observer Variation; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology
Utilidad del índice Doppler delta P/delta t en la evaluación de la disfunción sistólica ventricular izquierda.