RU2470578C1 - Method of determining reason of syncopes of different origin - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to field of medicine, namely cardiology. Clinical interrogation and electric cardiogram registration are carried out. During clinical interrogation presence of the following signs is estimated: provocation of syncopes by medical manipulations, pallor of integuments during syncope, provocation of attacks by prolonged orthostasis, hyperhydrosis after syncope, "blackout" before loss of consciousness, possibility of preventing loss of consciousness by changing body position from vertical to horizontal, rapid heartbeat before syncope, provocation of syncope by fast change of body position from horizontal to vertical, provocation of syncope by physical exercise, long disorientation after loss of consciousness attack and its amnesia. On the basis of obtained values vasovagal cause of syncope, epilepsy or orthostatic hypotension is determined.

EFFECT: method makes it possible to determine reasons of syncopes of different origin.

2 tbl, 2 ex

Description

The invention relates to medicine, namely to cardiology.

The latest data from modern diagnostic centers of the world indicate that the causes of attacks of loss of consciousness are still unclear in a significant proportion of patients. The Framingham study showed that among the general population, the cause of syncope remained unclear in 37% of cases, according to emergency hospitals in 17-33% of cases, and according to a survey in special units (SYNCOPE UNIT) in 18-20% of cases.

The cost of examining such patients remains high. According to the United States, the cost of examining 1 hospitalized patient with fainting is approximately $ 5,500, in the UK - about 1,000 pounds, in Italy - 3,5 thousand euros.

Thus, even at present, the results of examination of patients of this category do not look optimal.

Three factors can be identified that impede optimal diagnostic results. The first factor is a wide variety of causes leading to fainting and other attacks of impaired consciousness (epilepsy, hypoglycemia, narcolepsy). Considering all the possible causes of attacks of loss of consciousness, the patient needs to ask more than 100 questions regarding the factors provoking fainting, symptoms preceding loss of consciousness, observed during the unconscious state and the period when the patient "comes to his senses." It should also take into account information about the patient’s diseases of the cardiovascular system, nervous system, other organs and systems, to clarify the family history of the presence of bouts of loss of consciousness and sudden death in his relatives.

In order to confirm the clinical concept, the patient needs to carry out 17 special laboratory and instrumental examination methods, more than half of which are very expensive. This is the second factor preventing optimal results.

The third factor is the irrational use of available survey methods. When determining the nature of syncope, according to our data, the following methods are extremely irrationally used: X-ray computed and magnetic resonance imaging of the brain, ultrasound of the carotid arteries, standard electroencephalography, echocardiography, daily Holter ECG monitoring.

The prototype of the proposed method is a technique proposed by specialists of the European Community of Cardiology (ESC) in 2009 (Eur. Heart J., doi: 10.1093 / eurheart / ehp298). According to this technique, at the initial stage of examination of a patient with syncope, a clinical survey, an active orthostatic test, and registration of a standard ECG are performed. The data obtained allow us to divide patients into two groups: with a high and low risk of sudden cardiac death. In the high-risk group, special instrumental examination methods are performed to exclude the arrhythmic / cardiac nature of syncope, and in the low-risk group, special instrumental examination methods are used to exclude the vasovagal (reflex) nature of syncope.

The technique proposed by ESC specialists has several limitations:

1) at the initial stage of the examination, the patient has to answer a large number of questions (approximately 118), and the doctor analyze them;

2) contrary to obvious clinical symptoms indicating a diagnosis of vasovagal syncope, special expensive instrumental examination methods are performed (tilt test or passive long-term orthostatic test, long-term ECG monitoring using subcutaneous implantable devices), while the desire for mandatory electrocardiographic objectification of vasovagal syncope is not necessary , since the data obtained today cannot accurately determine the choice of therapeutic measures.

The problem to be solved in the present invention is the development of a method for differential diagnostic examination of patients with syncope of various origins.

Achievable technical result is to determine the cause of fainting of various origins.

Of 515 patients with a history of syncope, 208 patients were selected who had only one, strictly documented, cause of fainting attacks. In 52% of patients, the vasovagal nature of syncope was determined. Arrhythmic syncope was represented by: paroxysmal ventricular tachycardia - 20%, transient atrioventricular block - 4%, sinus node weakness syndrome - 3% and paroxysmal supraventricular tachycardia - 1%. Epilepsy was diagnosed in 13% of patients, syncope as a result of orthostatic hypotension in 7% of patients. Depending on the identified cause, all patients were conditionally divided into 2 groups: the first - vasovagal syncope (109 patients), the second - all other causes (99 patients). All patients underwent a special questionnaire on 122 questions, the results of which were subjected to mathematical processing in order to identify clinical signs that reliably divided the 2 groups of patients.

As a result of a mathematical multivariate analysis using logistic regression, 10 clinical signs were identified that were most significant for the separation of vasovagal syncope and other causes of seizures (Table 1).

Table 1. Clinical signs relevant to the separation of vasovagal syncope and other causes of seizures Clinical sign Xi 1. Provocation of syncope with medical manipulation X1 2. Pallor of the skin during fainting X2 3. Provocation of attacks with prolonged orthostasis X3 4. Hyperhidrosis after fainting X4 5. "Darkening in the eyes" before losing consciousness X5 6. The ability to prevent loss of consciousness by moving from a vertical to a horizontal position of the body X6 7. Rapid heartbeat before fainting X7 8. Provocation of fainting by a quick transition from horizontal to vertical position of the body. X8 9. Provocation of fainting with physical exertion. X9 10. Prolonged disorientation after an attack of loss of consciousness and its amnesia. X10

All of the above signs were designated as variables "X1-10". They entered the logistic regression model (function) (Q).

Q = 282 (X1) +124 (X2) +53 (X3) +36 (X4) +25 (X5) +7.4 (X6) -12 (X7) -31 (X8) -141 (X9) -206 (X10 )

The numbers before the variables “X1-10” are the coefficients with which these signs entered the presented function.

The calculation of the Q value reflects the number of points scored by patients during the survey. To calculate the value of the function Q, determine the sensitivity and specificity, an ROC analysis was performed. The value of the Q function, equal to 160 points, divided the patients into 2 groups: 1 - with vasovagal syncope and 2 - with other causes of seizures (with sensitivity = 98% and specificity = 98.5%). This is the optimal value of the function, in which the ROC analysis gives the maximum values of both sensitivity and specificity.

The patient has a vasovagal cause of fainting if he gains more than 160 points in total, and another reason for the attacks if the total score is 160 or less.

The next step was an attempt to separate other causes of fainting attacks, which were represented by arrhythmic syncope, epileptic seizures, and syncope as a result of orthostatic hypotension. The results of the study showed that the use of this function does not allow to reliably separate the indicated causes of loss of consciousness attacks using only clinical symptoms. In this regard, other clinical and instrumental symptoms included in the program of the initial examination of the patient were analyzed. These signs are presented in table 2.

table 2 Additional clinical and instrumental symptoms, allowing to differentiate arrhythmic and epileptic attacks of loss of consciousness, as well as fainting due to orthostatic hypotension Signs Arrhythmic syncope (n = 59) Epileptic seizures (n = 26) Orthostatic hypotension (n = 14) 1. ECG / HMECG / ECHOCG changes indicating the possibility of arrhythmic syncope 49 (83%) 2 (8%) 2 (14%) 2. Disorientation and amnesia of an attack of loss of consciousness "0" 21 (81%) "0" 3. Decrease in GARDEN> 20 mmHg with the development of a presyncopal / syncopal attack with active orthoprobe "0" "0" 12 (86%) Note. GARDEN - systolic blood pressure.

ECG / HMECG / ECHOCG changes indicating the possibility of arrhythmic syncope:

- documented persistent tachycardia paroxysms with narrow and broadened QRS complexes recorded after syncope,

- asystole due to episodes of “stopping” the sinus node, sinoatrial and AV block> 3 seconds,

QT interval lengthening> 500 ms

- Brugada similar ECG changes,

- bifascicular blockade, WPW phenomenon,

- ECG-documented paroxysms of flickering - atrial flutter,

- post-infarction cicatricial changes,

- myocardial hypertrophy / expansion of the heart.

According to the data of the present study, the first sign occurred in 83% of cases in patients with documented arrhythmic syncope, in 8% of cases in patients with epileptic seizures, and in 14% of cases in patients with orthostatic hypotension, i.e. the sensitivity of this trait was 83%, and the specificity was 90%.

The second symptom was found in 81% of patients with documented epilepsy and was not observed with arrhythmic and orthostatic syncope, i.e. the sensitivity of this trait was 81%, and the specificity was 100%.

The third symptom according to the present study was found in 86% of cases in patients with fainting due to orthostatic hypotension and did not occur in all other cases. The sensitivity of this trait was 86%, and the specificity was 100%.

As a result of a retrospective analysis of clinical and instrumental data, a new method for the differential diagnosis of syncope of various origins was created.

The proposed method is as follows.

A clinical survey of the patient is carried out using a questionnaire containing 10 questions (see table 1). Each evaluated attribute has 2 answers: “YES” or “NO”, which are assigned the value “1” or “0”, respectively. The obtained answer values are substituted into the formula (instead of the variables X1-10) to calculate the Q value:

Q = 282 (X1) +124 (X2) +53 (X3) +36 (X4) +25 (X5) +7.4 (X6) -12 (X7) -31 (X8) -141 (X9) -206 (X10 )

In addition to a clinical survey (questionnaire), a standard ECG is recorded.

If Q is more than 160 points and signs of arrhythmic syncope are not detected during ECG registration, the diagnosis of vasovagal syncope is established. In this case, the patient does not need further instrumental examination.

The diagnosis of vasovagal syncope is also established if Q is less than 160, ECG registration does not reveal signs indicating arrhythmic syncope, with an active orthostatic test, systolic blood pressure (BP) does not decrease by more than 20 mmHg, the answer is 10- The question on the questionnaire is negative, and the result of at least one of the samples inducing vasovagal syncope, namely: a long orthostatic test (DOP), a bicycle ergometry test (VEM), and massage of synocarotid zones (ISSC) are positive.

If Q is less than 160 points, then an active orthostatic test is additionally performed. If during an active orthostatic test, a decrease in systolic blood pressure by more than 20 mm RT is detected. Art., which is accompanied by the development of a pre-syncope or fainting, the diagnosis of orthostatic hypotension as a cause of fainting is established.

If Q is less than 160 and signs of arrhythmic syncope are detected during ECG recording, Holter monitoring or intracardiac electrophysiological examination is performed. And if signs of arrhythmia associated with syncope (ventricular or supraventricular tachycardia, episodes of cardiac arrest) are detected during Holter monitoring, or the same arrhythmia is induced during intracardiac electrophysiological examination, then it is established that the cause of syncope is arrhythmia.

If Q is less than 160, the answer to the 10th question of the questionnaire is positive, then an EEG study is performed. And when signs of epilepsy are detected on the EEG, it is established that the cause of syncope is epilepsy.

To check the operability of the created method of differential diagnostic search and the proposed questionnaire function (Q), a “control” group of 76 patients with attacks of loss of consciousness was recruited.

The verification feature was a comparison of the results of two methodological approaches: 1) the newly created and 2) standard, which is widely used at present in hospitals in Russia and abroad.

Following the newly created diagnostic search method, at the first stage, all patients were asked to fill out a special questionnaire in writing, containing 10 questions, using only two answers “Yes” or “no”, which were assigned the values 1 or 0. In the future, according to a special formula Q the total score was calculated.

47 patients during the questionnaire scored more than 160 points, of which in 2 patients on the standard ECG factors of "arrhythmic" risk were noted. Following the newly created approach, 45 patients (59%) did not need further instrumental examination to confirm the diagnosis of vasovagal syncope, since it was obvious, and the examination was continued for 2 patients (with “arrhythmic” risk factors for ECG). 29 (38%) patients scored less than 160 points, their examination was continued. In total, 31 patients needed instrumental examination methods to accurately verify the cause of the attacks of loss of consciousness. The next stage of the examination was: 1) conducting and analyzing the results of ECG, Holter monitoring (XM) of ECG and echocardiography (ECHOCG); 2) conducting an active orthostatic test; 3) assessment of the answer to the 10th question of the questionnaire.

In 20 patients (26.3%), ECG / HMECG / ECHOCG showed changes indicating a potential risk of arrhythmic syncope. These patients underwent a special examination (long-term monitoring of the ECG and / or intracardiac EFI), according to which the association of syncope with impaired conduction and heart rhythm was confirmed in 17 cases.

1 patient during an active orthostatic test showed a decrease in systolic blood pressure from 110/80 to 70/40 mm Hg. with the occurrence of a fainting state. He was diagnosed with orthostatic hypotension.

3 patients answered positively to question 10 of the questionnaire, which could indicate the epileptic mechanism of fainting attacks. An EEG examination confirmed the diagnosis of epilepsy in 2 cases (2.6%) out of three.

11 patients underwent examination methods aimed at confirming the vasovagal cause of seizures (DOP / VEM), according to the results of which vasovagal syncope was identified in 4 patients.

Repeated examination (long-term ECG monitoring) conducted in 7 patients revealed arrhythmias as the cause of syncope in 3 patients.

Thus, the cause of the attacks of loss of consciousness was determined in 72 of 76 patients - 94.7%. In 49 cases (64.5%), vasovagal syncope was diagnosed, in 20 cases (26.3%) the arrhythmic nature of syncope was detected, in 2 cases (2.6%) the epileptic genesis of seizures was determined and in 1 case (1.3%) diagnosed with orthostatic hypotension. Only in 4 patients (5.3%) did the nature of the seizures remain unknown.

The results obtained using the new approach were compared with the results of the standard approach.

Using a new approach, it was possible to reduce the percentage of patients whose diagnosis was unclear from 18.4% to 5.3%. The increase in the diagnostic effectiveness of the “new” approach was due to an increase in the percentage of patients with diagnosed vasovagal syncope.

High indices of sensitivity = 90% and specificity = 100% were noted when checking the created questionnaire to predict the vasovagal nature of syncope in the “control” sample of patients.

It is important that, despite a significant decrease in the volume of instrumental examination, the accuracy of the diagnosis of non-neovaginal (arrhythmias, epilepsy, orthostatic hypotension) causes of loss of consciousness attacks using the new approach coincided with the accuracy of the "standard" approach.

The need for the use of HMECG, echocardiography and an active orthostatic test has decreased by more than half with the use of a new approach compared to the standard approach. The indicators reflecting the need to use special methods to confirm the arrhythmic nature of syncope were similar for the two approaches. The need to use instrumental methods confirming the epileptic and vasovagal genesis of seizures significantly decreased with the new approach compared to the standard approach.

Thus, the examination of patients with syncope using the new approach had clear advantages over the "standard" approach, which was as follows:

1) in increasing diagnostic efficiency;

2) a significant reduction in the number of instrumental examination methods necessary for accurate verification of the diagnosis, i.e. there was a decrease in economic costs.

Clinical example No. 1. Patient B., 20 years old, sent to the Institute of Cardiology. A.L. Myasnikov to clarify the genesis of syncopal conditions. Fainting from 12 years of age, occurred with a frequency of 1 time in 2-3 years. For all time - 4 attacks of loss of consciousness. Fainting was observed in the orthostatic position of the body (with prolonged standing in the heat). One of the syncopal seizures was triggered by a painful injection (vaccination at school). The loss of consciousness was preceded by a feeling of “darkening in the eyes” and nausea, eyewitnesses noted the short duration of the unconscious period (several seconds), and the pallor of the skin. After fainting, marked hyperhidrosis (“cold, sticky sweat”) was noted. Once the patient was able to prevent loss of consciousness by the fact that he managed to lie down at the moment of sensation of the precursors of the attack.

Standard approach. The following examination methods were performed on the patient: standard ECG (sinus rhythm with heart rate of 68 beats / min, normal duration of the PQ interval, QRS complex, QT interval), daily HMECG (average heart rate per day = 63 beats / min, minimum heart rate at night during sleep = 37 beats / min, maximum heart rate during physical activity during the day = 181 beats / min - ice skating, cardiac arrhythmias and pauses in heart function> 2 seconds were not registered), echocardiography (normal sizes of heart cavities, absence of myocardial hypertrophy, fraction ventricular ejection = 76%), active orthostatic Sample (lying BP numbers = 110/60 mm Hg, standing for 5 minutes, BP numbers = 110/74 mm Hg), EEG with provocative samples (data for the presence of epileptiform activity were not obtained), head MRI brain (no pathology was detected), ultrasound of vessels of the brachiocephalic system (no pathology was detected), DOP (vasovagal syncope was induced during the test).

A new approach. The total score scored during the survey was 527.4, which indicated the obvious vasovagal nature of syncope. According to the new approach, the patient who scored more than 160 points during the questionnaire and has a normal standard ECG does not need further examination.

Thus, in this clinical case, when applying the new approach, it seems quite obvious: 1) the diagnostic benefit in the form of a quick and accurate verification of the cause of the attack, based only on the analysis of the patient’s clinical survey, and 2) the economic benefit in the form of a reduction (absence) of costs instrumental examination.

Clinical example No. 2. Patient V., 73 years old, turned to the Cardiology Institute named after A.L. Myasnikov with complaints of repeated attacks of loss of consciousness. Attacks disturb the patient for the past 2 years. For all the time there were 6 fainting. Attacks occurred without obvious provoking factors. Twice the loss of consciousness was preceded by short-term sensations of dizziness and “darkening in the eyes,” after the patient fell and “came to,” felt a rapid heartbeat.

Standard approach: ECG (sinus rhythm with a heart rate of 75 beats / min, blockade of the anterior left branch and right leg of the His bundle - bifascicular block, interval PQ = 170 ms, duration of the QRS complex = 150 ms, interval QT = 440 ms), daily HMECG ( against the background of sinus rhythm, persistent intraventricular block is recorded, heart rate per day = 76 beats / min, minimum heart rate = 42 beats / min at night during sleep, maximum heart rate = 117 beats / min during walking, rhythm disturbance and pause in “work” heart> 2 seconds are not marked), echocardiography (cardiac cavities are not expanded, contractile ability of the myocar the left ventricle is normal - ejection fraction = 64%, no signs of cicatricial myocardial damage and hypertrophy were detected), an active orthostatic test (lying BP numbers = 146/80 mm Hg, standing for 10 minutes BP numbers from 140/86 to 150/90 mmHg), EEG (data for epileptiform activity not obtained), CT of the brain (no pathology detected), DOP (duration of orthostasis = 40 minutes, a sinus rhythm with a heart rate of 72 to 86 beats was recorded during the test) / min, blood pressure from 140/80 to 150/92 mm Hg, syncopal / presyncopal seizures are not induced). Thus, all the methods of instrumental examination performed (the “standard” approach) could not determine the cause of the attacks of loss of consciousness.

A new approach. The total score of the patient when questioning points = 13, which indicates the non-invasive nature of the attacks. According to the standard ECG, signs are identified that indicate arrhythmic syncope - the presence of a bifascicular block. The patient underwent prolonged (within 7 days) ECG monitoring, during which fainting took place. An ECG recorded an episode of complete transverse blockade with asystole of the heart lasting 8 seconds. According to the results of the examination, in order to prevent fainting, a pacemaker was implanted.

Therefore, the application of the standard approach was associated with the implementation of a large volume of instrumental examination methods, which did not give a positive result. The use of the new approach was diagnostically effective, and a significantly smaller volume of instrumental examination methods was required, which reduced the cost of verifying the cause of syncope.

Claims (1)

A method for determining the cause of syncope of various origins, including conducting a clinical survey and recording an electrocardiogram (ECG), characterized in that during a clinical examination the presence of signs is assessed: provocation of syncope with medical procedures (X1), pale skin during fainting (X2), provocation of attacks for a long time orthostasis (X3), hyperhidrosis after fainting (X4), “darkening in the eyes” before loss of consciousness (X5), the ability to prevent loss of consciousness by moving from vertical to horizontal body position (X6), rapid heartbeat before fainting (X7), provoking fainting by a quick transition from horizontal to vertical position of the body (X8), provoking fainting with physical exertion (X9), prolonged disorientation after an attack of loss of consciousness and amnesia (X10), each the attribute is assigned 1 point or 0 points for the answer: “YES” or “NO”, respectively, based on the received data, the Q value is calculated:
Q = 282 (X1) +124 (X2) +53 (X3) +36 (X4) +25 (X5) +7.4 (X6) -12 (X7) -31 (X8) - 141 (X9) -206 (X10)
and with a Q value greater than 160 and the absence of signs on the ECG indicating arrhythmic syncope, or with a Q value less than 160 and the absence of signs on the ECG indicating arrhythmic syncope, as well as in the absence of a decrease in systolic blood pressure (BP) of more than 20 mm Hg when conducting an active orthostatic test, the answer is “NO” to sign X10 and a positive result, at least one of the samples inducing a vasovagal syncope, namely: a long orthostatic test (DOP), a bicycle ergometry test (VEM), massage of sinocarotid zones (ICSC), determine the vasovagal cause of syncope;
when the Q value is less than 160 and if there are signs on the ECG that indicate arrhythmic syncope, as well as signs of arrhythmia associated with syncope, during Holter monitoring, or arrhythmia associated with syncope, is induced during intracardiac electrophysiological examination, determine the cause of syncope - arrhythmia,
if Q is less than 160, the answer is “YES” to symptom X10, the presence of signs of epilepsy on the electroencephalogram determines the cause of fainting - epilepsy,
when the Q value is less than 160, there is a decrease in systolic blood pressure (BP) by more than 20 mm Hg. when conducting an active orthostatic test, which is accompanied by the development of a pre-syncope or fainting, determine the cause of fainting - orthostatic hypotension.