METHOD FOR PREDICTING ISCHEMIC CARDIAC DISEASE Russian patent published in 2006 - IPC A61B5/02 A61B10/00 

FIELD: medicine, cardiology.

SUBSTANCE: the present innovation deals with carrying out two loading tests under electrocardiogram control. The first test should be carried out at medicine-free background, as for the second - after introducing therapeutic dosage of nitrovasodilator. Point-based evaluation of subjective signs of myocardial ischemia should be performed for every loading test, moreover, 2 points should be put if patient's feelings are typical for tension-free stenocardia, 1 point - if patient's feelings are doubtful for tension stenocardia, 0 points - if patient's feelings are completely nontypical for tension stenocardia. Point-based evaluation in alterations of ST electrocardiogram should be conducted for every loading test. Moreover, one should fulfill point-based evaluation for the response to nitrovasodilator. Then it is necessary to carry out complex evaluation of paired test and the higher this complex evaluation is the higher the chance for availability of ischemic cardiac disease. Each loading test should be carried out up to maximal age-based heart rate and/or pronounced total fatigue and/or intensive anginous-like pain; while carrying out point-based evaluation for the alterations of ST segment of electrocardiogram one should put 2 points in case if at loading maximum it has been registered any out of the following alterations of ST segment: depression at 200 mcV and more; elevation at 200 mcV and more in the lead without Q tooth or QS complex; horizontal depression at 100 mcV and more if before provoking impact ST segment had oblique-ascending or horizontal direction; 1 point should be put if the above-mentioned alterations of ST segment are registered not at the maximum of loading; 1 point should be put if during loading or during the first 5 min of restorative period it has been registered any of the following alterations of ST segment: elevation at 100-199 mcV in the lead without Q tooth or QS segment; oblique-ascending depression at 150-199 mcV; horizontal depression at 50-99 mcV, if before the provoking impact ST segment had oblique-ascending direction; oblique-descending depression at 50-99 mcV, if before provoking impact ST segment had either oblique-ascending or horizontal direction; horizontal depression at 100-199 mcV if before provoking impact ST segment had either horizontal or oblique-descending direction; oblique-descending depression at 100-199 mcV if before provoking impact ST segment had oblique-descending direction; 0 points should be put if during loading and during the first 5 min of restorative period it has not been registered neither of the following alterations of ST segment: elevation at 100 mcV and more in the lead without Q tooth or QS complex; oblique-ascending depression at 150 mcV and more; either horizontal or oblique-descending depression at 100 mcV and more; horizontal depression at 50 mcV and more if before provoking impact ST segment has oblique-ascending direction; oblique-descending depression at 50 mcV and more if before provoking impact ST segment had either oblique-ascending or horizontal direction. One should carry out point-based evaluation for the dynamics of arterial pressure for every loading test and 1 point should be put if during ascending loading it has been registered the decrease of systolic arterial pressure for 20 mm mercury column and more, 0 points should be put if during ascending loading it has not been registered the decrease of systolic arterial pressure for 20 mm mercury column and more. While performing point-based evaluation of subjective signs of myocardial ischemia patient's feelings should be considered to be typical for tension stenocardia if loading was stopped as a result of intensive pain at its duration being 60 sec not less localizing below the level of eyeballs and above umbilicus level; patient's feelings are considered to be doubtful for tension stenocardia if during loading or during the first 5 min of restorative period one should observe discomfort at its duration being for 60 sec not less localizing below the level of eyeballs and above umbilicus level that is not the cause of loading test cessation; patient's feelings are considered to be completely nontypical for tension stenocardia if patient has no complaints for pain or discomfort localizing below the level of eyeballs and above umbilicus level for 60 sec and more during loading test and during the first 5 min of restorative period. Then one should calculate the unified point-based evaluation for every loading test, moreover at the sum of point-based evaluation for the alterations of ST segment of electrocardiogram and point-based evaluation for the dynamics of arterial pressure ranged 0-2 points the above-mentioned unified point-based evaluation should be calculated by the following formula: UPE=PESSMI+PESTS+PEDAP-1, where UPE - the unified point-based evaluation; PESSMI - point-based evaluation of subjective signs of myocardial ischemia, PESTS - point-based evaluation of ST segment of electrocardiogram; PEDAP - point-based value for the dynamics of arterial pressure. Then it is necessary to evaluate D coefficient by the following formula: D=UPE₁-UPE₂-T₁+T₂, where UPE₁ - the unified point-based evaluation for the first loading test in points; UPE₂ - the unified point=based evaluation for the second loading test in points; T₁ - duration of the first loading, min; T₂ - duration of the second loading, min. Then on should conduct point-based evaluation for the response to nitrovasodilator and 3 points should be put if D coefficient is not less than 5; 2 points - if D coefficient is not less than 3; 0 points - if coefficient D is not less than 1. One should calculate complex evaluation of the paired test by the following formula: CEPT=UPE₁+PERN, where CEPT - complex evaluation of the paired test, UPE₁ - the unified point-based evaluation of the first loading test in points; PERN - point-based evaluation for the response to nitrovasodilator. In case of complex evaluation of the paired test being equal to 7 points at availability of 100% it is possible to diagnose ischemic cardiac disease in the form of tension stenocardia, at complex evaluation of the paired test ranged 4-6 points one should conclude upon ischemic cardiac disease as tension stenocardia at high degree of probability. In case of complex evaluation of the paired test being equal to 3 points one should consider the diagnosis of ischemic cardiac disease as tension stenocardia to be doubtful, and at complex evaluation of the paired test being below 3 points the diagnosis of tension stenocardia should be rejected at high degree of probability.

EFFECT: higher accuracy of ICD diagnostics.

7 cl, 3 ex, 11 tbl