Association of polymorphisms in endothelin-1 and endothelin receptor a genes with vasovagal syncope.

The endothelin system may play a role in the pathogenesis of vasovagal syncope (VVS) because it is implicated in blood pressure regulation. We hypothesized that endothelin-related genetic polymorphisms might modulate susceptibility to VVS. This study aimed to evaluate the possible influence of endothelin-1 (EDN1) and endothelin receptor A (EDNRA) gene variants on the occurrence of tilt-induced VVS and autonomic nervous system activity during the head-up tilt test (HUT). Results were expressed as mean +/- SEM. In 254 patients with recurrent syncope (age 45.33+/-1.22 years, 94 males, 160 females), heart rate variability (HRV) was measured during HUT. EDN1 rs5370 G>T and EDNRA rs5333 T>C gene polymorphisms were assessed using high-resolution melting analysis. There was no statistically significant association between polymorphisms EDN1 rs5370 and EDNRA rs5333 and positivity of HUT or hemodynamic types of VVS. Patients with GT or TT genotypes at the rs5370 locus of the EDN1 had significantly higher values of high-frequency (HF) and the standard deviation of the average NN intervals at the time of the syncope, and they tended to have lower low-frequency (LF) and LF/HF ratio when compared to homozygotes (GG). No statistically significant differences were found in HRV parameters concerning the EDNRA rs5333 genotypes. Our findings suggest the potential role of EDN1 rs5370 variants in regulating autonomic nervous activity and pathogenesis of VVS.

Beta 3 subunit of G-protein and its influence on autonomic nervous system in patients with vasovagal syncope.

OBJECTIVES: The aim of this prospective study was to investigate the impact of genetic polymorphisms of ß3 subunit of G-protein on the occurrence of vasovagal syncope, hemodynamic parameters and heart rate variability during head-up tilt test (HUT). BACKGROUND: G-proteins play an important role in the intracellular transmission of impulses in cardiovascular autonomic reflexes. METHODS: In 157 patients with suspected vasovagal syncope HUT was performed. Ninety-one patients (38 men, 53 women, mean age 48 ± 17 years) had positive HUT. Control group consisted of 109 subjects (69 men, 40 women, mean age 37 ± 16 years) with no history of syncope. Results of HUT, hemodynamic parameters and LF, HF, LF/HF, SDNN, RMSSD parameters of heart rate variability were compared in patients with different genotypes. C825T polymorphism of ß3 subunit of G-protein was determined in the study subjects. RESULTS: There was no significant difference in the distribution of genotypes between patients and control group. Also, there was no significant difference in hemodynamic parameters. A statistically significant difference was found between genotypes in LF/HF in the early HUT (mean rank CC: 48.68 vs CT: 35.51 vs TT: 34.14; p = 0.039) and at RMSSD at the time of syncope (mean rank CC: 32.38 vs CT: 42.74 vs TT: 18.50; p = 0.026). CONCLUSIONS: In this study, the relation of C825T polymorphism of ß3 subunit of G-protein to vasovagal syncope was not documented (Tab. 2, Fig. 4, Ref. 37).

Reduced baroreflex sensitivity in patients with vasovagal syncope.

OBJECTIVES: The evidence is conflicting regarding the role of baroreflex in patients with vasovagal syncope. The aim of the study was to measure baroreflex sensitivity (BRS) and hemodynamic parameters during head up tilt test (HUT) with nitroglycerine stimulation. METHODS: Nitroglycerine stimulated HUT was performed in 51 patients with the history of recurrent syncope (mean age 46±19 years, 18 men, 23 women). Cardiac output (CO), stroke volume (SV), left-ventricular ejection time (LVET) and total peripheral resistance (TPR) were assessed during HUT by volume-clamp method using a beat-to-beat photopletysmography. Spontaneous BRS sensitivity was computed using a sequential BRS calculation. RESULTS: HUT was positive after nitroglycerine administration in 28 patients and negative in 23 patients. BRS was lower at the time of syncope in HUT positive group compared to end-test values in HUT negative group (0.54±0.27 vs 0.72±0.35, p=0.03). At the time of syncope, CO was significantly lower in HUT positive patients compared to HUT negative patients (2.6±1.4 vs 4.3±1.4 l/min, p<0.0001), similarly as SV (34.7±14.7 vs 49.2±19 ml, p=0.005). LVET was significantly higher in syncopal patients (282.27±26.2 vs 240.5±58.8 ms, p=0.002) and TPR did not differ between two groups. CONCLUSIONS: Reduced BRS may contribute to the development of the vasovagal syncope by inability to adequately counteract hypotension resulting from decreased cardiac output at the time of syncope (Tab. 3, Ref. 18).

[Is there a relationship between inflammatory markers, oxidative stress and postoperative atrial fibrillation?]. / Existuje vztah medzi zápalovými markermi, oxidacným stresom a pooperacnou fibriláciou predsiení?

INTRODUCTION: Atrial fibrillation (AF) is one of the most common complications following heart surgery. The aim of this work was to verify the relationship between inflammatory markers, oxidative stress and postoperative arrhythmia. METHODS: 45 patients with ischemic heart disease (12 women and 33 men, mean age 62.3 ± 9.4 years) underwent surgical myocardial revascularization. The extracorporeal circulation (ECC) was used in 30 patients, without ECC was 15 patients. During the first 3 postoperative days was determining the incidence and duration of the AF, laboratory markers of inflammation (CRP, leukocytes, TNFα), malondialdehyde (MDA). RESULTS: Demographic data and associated disease were in this patients similar. The incidence of AF we documented in 30 patients (66.7%). In patients with postoperative AF were significantly higher levels of inflammatory markers (leukocytes 13.6 ± 3.6 vs 11.3 ± 3.6; 14.7 ± 3.9 vs 12.5 ± 2.9; 13.7 ± 4.1 vs 11.4 ± 13.7; p 0.05; CRP 138.1 ± 41.1 vs 69.9 ± 25.8; p 0.001; TNFα 11.3 ± 14.3 vs 8.7 ± 3.6; 12.1 ± 14.5 vs 8.7 ± 3.1; p 0.05) compared with patients who were free from AF. Values of MDA were not significantly different. CONCLUSION: Patients with post-operative atrial fibrillation were higher levels of inflammatory markers compared with patients with sinus rhythm but no significant differences in the levels of oxidative stress.

[The importance of contractile reserve in patients with resynchronization therapy]. / Význam globálnej kontraktilnej rezervy u pacientov s resynchronizacnou liecbou.

INTRODUCTION: Contractile reserve of the myocardium is a strong prognostic factor in patients with heart failure. The presence of a significant amount of myocardial fibrosis might lead to insufficient response to resynchronization therapy We assumed that pre-implantation examination of global contractile reserve will allow prediction of the response to resynchronization treatment. METHODS: 25 symptomatic patients (NYHA III) with severe systolic dysfunction [ejection fraction (EF) 28.9 ± 6.9%] with signs of electric asynchrony (QRS 120 ms) went through dobutamine echocardiography prior to resynchronization treatment. The global contractile reserve was determined from the change to EF at rest and at the peak of pharmacological burden (40 µg/kg/min). Patients with a rise in EF of more than 5% and/or endsystolic volume reduction of more than 15% after three months of resynchronization treatment were considered responders. RESULTS: Compared to non-responders, responders had higher increase in EF during dobutamine stress echocardiography (Δ 12.8 ± 7.4 % vs. Δ 3.4 ± 7.1 %, p = 0.0042). Three months from the initiation of resynchronization therapy, the global myocardial contractile reserve also significantly correlated with EF increase (r = 0.67, p = 0.007). The 6% increase in EF during dobutamin stress echocardiography predicted responders to resynchronization therapy with 83% sensitivity and 75% specificity. CONCLUSION: The global contractile reserve may play an important role in prediction of a response to resynchronization therapy.

[Resynchronization therapy for heart failure--still many question marks]. / Resynchronizacná liecba srdcového zlyhávania-- stále vel'a otáznikov.

At present, the potential benefit of resynchronization therapy, i.e. an improved quality of life and prolonged survival in patients with heart failure, is not achieved in every patient. The 30% non-response has prompted a search for new criteria predicting patient response to resynchronization treatment. An absence of mechanical dyssynchrony, viability of the myocardium and an inadequate positioning of the intracardiac left ventricular lead probably limit the response to resynchronization therapy. ECG remains essential for the selection of suitable patients.

[Why there is atrial fibrillation after cardiac operations?]. / Preco vzniká fibrilácia predsiení po kardiochirurgických operáciách?

Atrial fibrillation (AF) is the most frequent arrhythmias after cardiac operations. Its incidence ranges from 10-65%. Often there is a patient discomfort, prolongs hospitalization, increases costs of operation and may be permanent or recurrent course. The cause of postoperative AF is multifactorial. The prevention of non-pharmacological and pharmacological interventions. The conventional treatment strategies include monitoring ventricular rate, restoration of sinus rhythm and prevention of thromboembolic events. The development of effective therapies designed to decrease the high incidence of postoperative AF may be important in the future.

[BNP and echocardiographic parameters in patients with chronic kidney disease and dialyzed patients]. / BNP a echokardiografické parametre u pacientov s chronickými chorobami obliciek a dialyzovaných chorých.

We assessed the relation between BNP levels and some echocardiographic parameters of systolic and diastolic function of the left ventricle in 49 patients (mean age 69.39 +/- 8.47 years) with chronic kidney disease in different stages of chronic renal failure according to K/DOQI and in 45 subjects (mean age 52.6 +/- 14.85 years) on dialysis. Median for BNP in the group of patients with chronic renal failure was 132 pg/ml, and in dialysis subjects 320 pg/ml. None of our patients had clinical signs of heart failure during the last six months. Using a method of correlation matrix we found the left ventricular mass and its indexed value as a common indicator of increased BNP level in both groups of patients (dialysis patients, p = 0.0003, and p = 0.0005, respectively; patients with chronic renal failure, p = 0.03, and p = 0.04, respectively). Further analysis proved that in the group of dialysis patients the main determinants of increased BNP level were volumes of the left heart side: left ventricular end diastolic volume (p = 0.004), endsystolic volume (p = 0.01), and left atrial volumes (maximal, minimal, and total atrial stroke volume; p = 0.004, p = 0.009 and p = 0.04, respectively). In the group of patients with chronic renal failure the major contributors to increased BNP level were echocardiographic parameters of diastolic filling assessed from transmitral and pulmonary venous flow: E wave (p = 0.001), A wave (p = 0.01), E/A (p < 0.001), IVRT (p = 0.004), E/EDT (p < 0.0001), S wave (p = 0.01), D wave (p = 0.0003), S/D (p = 0.001), Ar duration (p = 0.02), and E/Vp (p = 0.003). No significant relation to left ventricular ejection fraction was found in both groups of patients. Our results suggest that the main determinant of increased BNP level in patients with different stages of chronic renal failure is diastolic dysfunction, whereas in dialysis patients high left heart volumes due to volume overload. The common denominator of high BNP level in both groups of patients is especially the left ventricular mass.

Left atrial volume as a predictor of heart function.

OBJECTIVES: This study was designed to identify an association between left atrial volume and systolic and diastolic functions of the left ventricle. BACKGROUND: Several studies have shown a relationship between the left atrial volume and different cardiovascular risk factors. METHODS: Transthoracic echocardiographic results of 268 patients (136 women and 132 men, mean age 60.2+/-17.3 years) were studied retrospectively. Key echocardiographic variables of systolic and diastolic function were related to the left atrial volume and its indexed value. RESULTS: The mean indexed left atrial volume in a subgroup of patients with normal echocardiography, was 25.3+/-6.7 ml/m2. Left atrial volume significantly (p<0.0001) increased in deteriorating diastolic function (impaired relaxation, pseudonormalized pattern, and restrictive physiology): 33.6+/-11.6, 48.7+/-21.8 and 84.5+/-60.5 ml/m2, respectively. There were also significant (p=0.0001) differences in cases with normal systolic function (EF>50 %) and systolic dysfunction (EF<50%): 37.9+/-24.1 vs 54.9+/-34.7 ml/m2. There were no significant differences in the left atrial volumes (33.1+/-10.9 ml/m2 and 38.3+/-15.4 ml/m2, p=0.13) in patients with normal systolic function and impaired relaxation compared to patients with systolic dysfunction. However, in both cases these values were different from those with normal echocardiography (p<0.0001). In multiple regression analysis the best predictor of enlarged left atrial volume was the left ventricular mass. CONCLUSION: We found a strong association between left atrial volume and left ventricular systolic and diastolic dysfunction. The strongest association appeared between increasing left atrial volume and left ventricular mass (Tab. 2, Fig. 4, Ref. 26). Full Text (Free, PDF) www.bmj.sk.

Gene polymorphisms of renin angiotensin system and serotonin transporter gene in patients with vasovagal syncope.

UNLABELLED: Objective of this study was to compare the distribution frequencies of gene polymorphisms of renin-angiotensin and serotonin system in patients with positive and negative head- up tilt test (HUT). METHODS: DNA from 191 patients (mean age 44+ 18 years, 61 men) was collected. HUT was positive in 117 and negative in 74 patients. Following gene polymorphisms were determined by the PCR method: ACE insertion/deletion (I/D ACE), angiotensinogen (AGT) (M 235), angiotensin II receptor (ATR1) (A 1166C) and serotonin transporter (SERT) polymorphism (5HTTLPR). RESULTS: No significant differences in the distribution of gene polymorphisms between syncopal patients with positive and negative HUT were dectected. Distribution of polymorphisms included: I/D ACE: II 19 vs 20%, ID 55 vs 52%, DD 26 vs 28%. Angiotensinogen gene polymorphism MM 27% vs 30%, MT 48% vs 46%, TT 25% vs 24%. ATR1 polymorphism AA 44 vs 32%, AC50 vs 60%, CC 6 vs 8%, 5HTTLPR serotonin transporter gene polymorphism LL 42 vs 43%, SL 41 vs 39%, SS 17 vs 18%. CONCLUSIONS: An association between polymorphisms of ACE, AGT, ATR1 and SERT gene, and predisposition to VVS was not proven by the present study (Tab. 2, Ref. 22). Full Text (Free, PDF) www.bmj.sk.

Quality of life and psychological well-being in patients with various pacing modes.

AIM: of the study was to assess the influence of different pacing modes on the quality of life (QOL), anxiety and depression. METHODS: QOL was assessed in 101 patients (58 men, mean age 69.39 +/- 14.64 years) with implanted pacemaker (35 patients received VVI pacemaker, 17 patients VVIR, 21 patients DDD, 28 patients DDDR). QOL was measured by the SF-36 and Aquarel questionnaires, anxiety by Beck scale and depression by Zung scale. RESULTS: No differences in QOL were observed between patients with single chamber and dual chamber pacing. Patients with rate-adaptive pacing had higher scores in SF 36 scales (physical component summary, mental component summary, vitality and bodily pain), Aquarel (chest pain and dyspnea) and they exhibited lower degree of anxiety and depression compared to non-rate-adaptive pacing. Differences were shown only in a group of dual chamber pacemakers, not in the group of single chamber pacemakers. There was a strong correlation between the degree of anxiety and depression and the QOL in pacemaker patients. CONCLUSION: Dual chamber rate-adaptive pacing offered better QOL and psychological profile compared to dual chamber non-rate-adaptive pacing. No differences were observed between single chamber and dual chamber pacing (Tab. 3, Fig. 3, Ref. 24).

[ECG changes in alcoholic intoxication]. / EKG zmeny pri akútnej intoxikácii alkoholom.

Patients with acute alcohol intoxication often present with pathological electrocardiographic (ECG) changes. The changes are more frequent and prognostically more significant in chronic alcoholics, in patients with ischaemic heart disease (IHD), in alcohol cardiomyopathy or another organic heart disease, but they can also occur in young and healthy individuals. The typical ECG changes in inebriety are disturbances of heart rate having the nature of electric impulse generation disorder or of impulse conduction pathology. In persons without clinical evidence of heart disease, they are classified as 'holiday heart syndrome'. The most frequent tachyarrhythmia is atrial fibrillation; less frequent but prognostically much more significant is torsades de pointes (TdP) polymorphous ventricular tachycardia. Among bradyarrhythmias, the most significant is alcohol-induced sinus bradycardia which may be manifested by recurrent syncope. The higher the blood alcohol concentration, the higher the occurrence of a significant extension of ECG intervals with possible manifestation of latent conduction disturbance or even sudden cardiac death. Apart from heart rate disturbances, ECG picture very often shows non-specific repolarisation changes. Ischaemia, which is mostly asymptomatic in the form of silent myocardial ischaemia, is worsened in alcohol-intoxicated IHD patients. The resulting ECG may be to a large extent influenced by states which often associate with inebriety, such as hypothermia, hypoglycaemia or electrolyte imbalance. ECG changes similar to those due to acute alcohol intoxication are also present in acute abstinence syndrome, especially in delirium tremens. There is convincing evidence that not only chronic alcoholism, but also single episodes of excessive alcohol consumption are associated with increased cardiovascular mortality.

Relation of various degrees of body mass index to systolic and diastolic dysfunctions.

OBJECTIVES: This study was designed to identify any associations between left ventricular function and obesity using clinical two-dimensional echocardiographic and Doppler studies. METHODS: We retrospectively evaluated 260 consecutive clinical echocardiographic findings. Key echocardiographic variables of systolic and diastolic function were related to various degrees of body mass index. RESULTS: In multiple regression analysis in the whole group of patients there was significant relation of body mass index to left ventricular mass and its indexed value (p < 0.0001). Multiple regression analyses in subgroups of patients according to systolic and diastolic function or dysfunction revealed similarly the strongest association of body mass index to mainly left ventricular mass. In subgroups of patients classified on the basis of their body mass indices significant differences were found also in case of left ventricular mass as well as left atrial volume (p = 0.0001, and p = 0.003, respectively). There was no association between body mass index and systolic or diastolic dysfunction. CONCLUSION: We found strong association between obesity and left ventricular mass. Obesity was not related to systolic and diastolic function or dysfunction.

Diagnostic yield of adenosine and nitroglycerine stimulated tilt test in patients with unexplained syncope.

OBJECTIVES: We aimed to compare diagnostic yield of adenosine tilt test (A-HUT) with nitroglycerine tilt test (NTG-HUT) in patients with unexplained syncope and to assess the use of adenosine tilt test as an alternative to routine tilt testing. BACKGROUND: Adenosine could provoke a vasovagal response in susceptible patients. Adenosine stimulated tilt testing is less time consuming than conventional tilt testing. METHODS: Forty-one consecutive patients with unexplained syncope were tested (29 females /12 males; mean age 44 +/- 20 years). As a part of standard diagnostic testing they undewent both adenosine and nitroglycerin stimulated tilt testing in random fashion. RESULTS: NTG-HUT was positive in 28 patients (68%). Six patients (14.6 %) developed a vasovagal response after adenosine stimulated head-up tilt test (A-HUT). All patiens with positive A-HUT showed also the positivity of NTG-HUT. No patient from with negative NTG-HUT developed a vasovagal response after adenosine induction. The diagnostic yield of NTG-HUT was significantly higher than yield of A-HUT (p < 0.001). The diagnostic yield of A-HUT was significantly affected by age. Subjects with a positive adenosine tilt test were younger than those with a negative tilt (29 +/- 10 vs. 46 +/- 20 years, p = 0.016). Five of six positive patients were <30 years of age. Diagnostic yield in those patients was 31%, whereas in patients >30 years of age was significantly lower (4%, p = 0.007). CONCLUSION: Diagnostic yield of the adenosine stimulated tilt testing is significantly lower than diagnostic yield of nitroglycerine stimulated tilt testing. Given the very short time needed for performing adenosine stimulated HUT, it may be useful in patiens <30 years of age. In this group of patiens positive adenosine-stimulated HUT may obviate need for the time consuming nitroglycerine-stimulated HUT (Tab. 1, Fig. 3, Ref. 17).

[Dobutamine exercise echocardiography versus SPECT in diagnosing ischemic heart disease]. / Dobutamínová zát'azová echokardiografia vs SPECT pri diagnostikovaní ischemickej choroby srdca.

UNLABELLED: The aim of the study was comparison of dobutamine stress echocardiography with SPECT in the assessment of ischemic heart disease. METHODS: It is a retrospective study analysing 119 patients (72 women and 47 men, mean age 56.9 +/- 10.68 years), who underwent dobutamine stress echocardiography and SPECT. Because of inconclusive findings (LBBB, decreased myocardial perfusion by SPECT depending on the position of the body), 23 patients were excluded. RESULTS: In the whole group of 96 patients the diagnostic validity of dobutamine stress echocardiography was as follows: sensitivity 78%, specificity 93%, positive predictive value 89%, negative predictive value 85%, and kappa value 0.71. In women the sensitivity was 69%, specificity 93%, positive predictive value 79%, negative predictive value 89%, and kappa value 0.64. In men the diagnostic validity was: sensitivity 83%, specificity 92%, positive predictive value 95%, negative predictive value 73%, and kappa value 0.70. CONCLUSION: In conclusion, dobutamine stress echocardiography is highly sensitive and specific method in the diagnosis of ischemic heart disease with good agreement when compared with SPECT. Because of availability and lower cost in comparison with SPECT, dobutamine stress echocardiography is an optimal method in the diagnosis and management of patients with ischemic heart disease in routine clinical practice.

[Diagnostic benefit of the use of implanted loop recorder (Reveal Plus) for patients with syncope with unclear aetiology]. / Diagnostický prínos pouzitia implantovaného sluckového rekordéra (Reveal Plus) u pacientov so synkopou nejasnej etiológie.

UNLABELLED: The objective of the study was to evaluate the diagnostic yield of a loop recorder (Reveal Plus, Medtronic) in the diagnosis of syncope conditions whose aetiology remains unclear despite the performance of a full diagnostic procedure. PATIENTS AND METHOD: Loop recorders were implanted in 25 patients with recurrent syncope (9 men, 16 women, average age 59 +/- 14 years), who reported 4 +/- 2.7 episodes of syncope (2-10 episodes). A complete diagnostic algorithm was performed for all patients before implantation including the head-up tilt test, an invasive electrophysiological examination and a neurological examination. The aetiology of the syncope was not established by these examinations. RESULTS: During an average monitoring period of 13 +/- 8 months (1-24 months) 10 patients experiences recidivating syncope, 7 patients experienced pre-syncope and 1 patient experienced palpitations. 7 were asymptomatic during monitoring. Symptomatic arrhythmia was detected in 10 patients (40%). The most frequent finding was bradyarrhythmia (6 patients--sinus arrest in 3 patients, serious bradycardia in 2 patients, AV block in 1 patient). Tachyarrhythmia was the cause of symptoms in 4 patients (supraventricular tachycardia in 3 patients, ventricular bigeminy in 1 patient). In the case of 5 patients (20%) syncope (pre-syncope) took place in the absence of a serious arrhythmia and was classified as vasovagal syncope. CONCLUSION: The implantable loop recorder established a diagnosis in 15 of 25 patients (60%) with syncope that was not diagnosed by conventional tests and it is a highly beneficial method for diagnosing syncope.

[The importance of anamnesis in differential diagnosis of reflex and cardiogenic syncope]. / Význam anamnézy v diferenciálnej diagnostike reflexných a kardiogénnych synkopálnych stavov.

UNLABELLED: The aim of the study was to establish the difference in the anamnestic data in cardiogenic and reflex syncope during a systematic gathering of data using a structured questionnaire and to measure the benefits of structured clinical history in differential diagnosis of syncope. METHODOLOGY: 70 patients with syncope of undetermined etiology (average age 51 years, 26 men and 44 women) underwent a standard diagnostic protocol procedure. Cardiogenic syncope was diagnosed in 16 patients (23%), vasovagal syncope in 34 patients (49%), in 20 patients (28%) the cause of the syncope remained uncertain. Anamnestic data was collected through a structured questionnaire which contained 70 points. OUTCOME: Patients with cardiogenic syncope, as opposed to those with vasovagal syncope, tended to show higher age (68 vs. 43 years, p < 0.001), higher occurrence of IHD (75% vs. 35%, p = 0.008) and hypertension (62% vs. 29%, p = 0.02). Cardiogenic syncope in the prodromal phase exhibited a more frequent feeling of weakness (43% vs. 14%, p = 0.02), absence of the typical provoking factor (56% vs. 15%, p < 0.001), unspecific occurrence during the day (81% vs. 41%, p = 0.008), and weak pulse according to witness report (50% vs. 8%, p = 0.01). There was a significantly higher incidence of visual disturbances in vasovagal syncope in the prodromal phase (47% vs. 19%, p = 0.05) and sweating (29% vs. 6%, p = 0.05), provoking factors often involved long standing on feet (66% vs. 25%, p = 0.01) and hunger (29% vs. 0%, p = 0.01), and paleness was often reported by witnesses as opposed to vasovagal syncope (91% vs. 31%, p = 0.04). The rate of occurrence of palpitation and nausea in the prodromal phase was identical in both types of syncope. CONCLUSION: There exists a significant difference in anamnestic data of patients with cardiogenic syncope and those with vasovagal syncope. Derailed clinical history is a useful method in differential diagnosis of syncope.

Role of the peripheral serotoninergic system in the pathogenesis of vasovagal syncope.

OBJECTIVE: To evaluate the role of peripheral serotoninergic system in the pathogenesis of vasovagal syncope. BACKGROUND: Increased central serotoninergic activity was suggested to play a role in sudden inhibition of sympathetic activity responsible for the genesis of vasovagal syncope. There is good correlation between the central serotoninergic activity and the plasma levels of serotonine. METHODS: In twenty-two patients (mean age 48 +/- 19 years, 10 men, 12 women) with suspected vasovagal syncope head-up tilt test (HUT) was performed. Passive HUT (60 degrees, 20 minutes) was followed, if negative, by nitroglycerine stimulated HUT (400 microg sublingually, 15 minutes). Blood samples were obtained at baseline (in supine position), in 5 minute, 15 minute of HUT and finally at syncope or end of the test. Plasma levels of serotonine were measured by enzyme-immunoassay (EIA) method. RESULTS: HUT was positive in fifteen patients and negative in seven patients. In all HUT positive patients syncope developed after nitroglycerine stimulation. Mean duration of nitroglycerine phase was 4.8 +/- 1.2 min. In 5 min of HUT serotonine level was significantly lower in HUT positive patients HUT (102.40 +/- 43.11 vs 160.85 +/- 43.71 ng/ml, p = 0.01). At the time of syncope no significant differences were observed between HUT positive and HUT negative patients (184.26 +/- 118.72 vs 196.57 +/- 88.91 ng/ml, p = 0.40). CONCLUSION: In patients with vasovagal syncope lower level of plasma serotonine were observed during early HUT when compared to controls. No differences in serotonin activity were observed at the time of syncope (Tab. 1, Fig. 1, Ref. 24).

[Dynamic changes in the QT interval during the head-up tilt test in patients with vasovagal syncope]. / Dynamické zmeny QT intervalu pocas head-up tilt testu u pacientov s vazovagálnou synkopou.

Dynamic changes of the QT and QTc interval as well as QT dispersion and QTc dispersion during the head-up tilt test were investigated in 15 patients (8 men, mean age 32 years) with vasovagal syncope (VVS) and a positive head-up tilt test and in a control group of 15 patients with syncope in the case-history and a negative head-up tilt test (9 men, mean age 33 years). The value at rest of the QT interval did not differ in patients with VVS and controls. In controls at the beginning of HUT shortening of QT occurred (0.447 sec. vs. 0.419 sec. p = 0.0002), subsequently the QT did not change significantly. In patients with VVS during the beginning of the test only an insignificant shortening of QT occurred, while during the development of the syncope QT was prolonged (0.394 sec. vs. 0.420 sec. p < 0.0001). QT corrected for the pulse rate (QTc) did not change significantly during HUT. QTc dispersion was in patients with VVS significantly lower 3 minutes before the development of the syncope (0.067 sec. vs. 0.085 sec. p = 0.03), which may indicate the decline of the sympathetic and increase of the parasympathetic tonus which subsequently leads to the development of vasovagal syncope. QTc dispersion before the test was higher in patients with VVS as compared with controls (0.087 sec. vs. 0.063 sec., p = 0.03), which suggests an increase in the baseline sympathetic tonus in patients with VVS.

[Analysis of heart rate variability during the head-up tilt test in patients with vasovagal syncope]. / Analýza variability srdcovej frekvencie pocas head-up tilt testu u pacientov s vazovagálnou synkopou.

Changes of the autonomous nervous tonus are considered the most important factor in the pathogenesis of vasovagal syncope. In order to investigate changes of the autonomous tonus the authors examined in patients with vasovagal syncope the variability during the head-up tilt test (HUT). In 35 patients with assumed vasovagal syncope the authors used a passive HUT (45 mins., 60 degrees) and subsequently nitroglycerin-stimulated HUT (0.4 mg s.l, 15 mins.). The heart rate variability was evaluated before the onset of the test in a horizontal position, immediately after tilting the patient (0 min.), during the 5th, 10th, 15th minute of the passive test, during the 5th minute of the nitroglycerin test, during the appearance of symptoms and after termination of the test in a horizontal position. They compared the results between a group of 20 patients with positive HUT (13 men, 36 years) and in 15 patients with a negative HUT (7 men, 32 years). The parameters of heart rate variability were during the development of the syncope (mean 6.4 mins. after administration of NTG) as compared with corresponding values in patients with negative HUT (during the 5th minute after administration of NTG) as follows: RR interval 759.6 +/- 248.1 ms vs. 552.1 +/- 88.7 ms (p = 0.01), SDNN 44.8 +/- 49.6 vs. 29.9 +/- 18.3 (p = 0.001), RMSSD 31.8 +/- 34.9 vs. 15.2 +/- 10.2 (p = 0.03), LF 4.44 +/- 0.66 lnms2 vs. 4.38 +/- 0.53 lnms2 (p = 0.82), HF 4.44 +/- 0.57 lnms2 vs. 4.39 +/- 0.45 lnms2 (p = 0.82), LF/HF 0.99 +/- 0.03 vs. 0.99 +/- 0.02 (p = 0.90). On development of the first presyncopal manifestations the statistical parameters of heart rate variability in patients with positive HUT were significantly higher as compared with patients with negative HUT, which suggests an increase of the parasympathetic autonomous tonus during the development of the vasovagal syncope.