Comparison of arterial stiffness parameters in patients with coronary artery disease and diabetes mellitus using Arteriograph.

Recently an expert consensus document advised to standardize user procedures and a new cut-off value for carotid-femoral pulse wave velocity in daily practice. Our aim was to observe aortic pulse wave velocity (PWVao) and augmentation index (AIXao) in two high cardiovascular risk groups: patients with verified coronary artery disease (CAD) or with type 2 diabetes mellitus (T2DM). We also aimed to determine the cut-off values for PWVao, AIXao in CAD and T2DM patients using oscillometric device (Arteriograph). We investigated 186 CAD and 152 T2DM patients. PWVao and AIXao increased significantly in the CAD group compared to the age-, gender-, blood pressure-, and heart rate-matched control group (10.2+/-2.3 vs. 9.3+/-1.5 m/s; p<0.001 and 34.9+/-14.6 vs. 31.9+/-12.8 %; p<0.05, respectively). When compared to the apparently healthy control subjects, T2DM patients had significantly elevated PWVao (9.7+/-1.7 vs. 9.3+/-1.5 m/s; p<0.05, respectively), however the AIXao did not differ significantly. The ROC-curves of CAD and healthy control subjects explored cut-off values of 10.2 m/s for PWVao and 33.23 % for AIXao. Our data provide supporting evidence about impaired arterial stiffness parameters in CAD and T2DM. Our findings encourage the implementation of arterial stiffness measurements by oscillometric method in daily clinical routine.

Physiological regulation of cardiac contractility by endogenous reactive oxygen species.

Increased production of reactive oxygen species (ROS) has been linked to the pathogenesis of congestive heart failure. However, emerging evidence suggests the involvement of ROS in the regulation of various physiological cellular processes in the myocardium. In this review, we summarize the latest findings regarding the role of ROS in the acute regulation of cardiac contractility. We discuss ROS-dependent modulation of the inotropic responses to G protein-coupled receptor agonists (e.g. ß-adrenergic receptor agonists and endothelin-1), the potential cellular sources of ROS (e.g. NAD(P)H oxidases and mitochondria) and the proposed end-targets and signalling pathways by which ROS affect contractility. Accumulating new data supports the fundamental role of endogenously generated ROS to regulate cardiac function under physiological conditions.

The influence of on-pump and off-pump coronary artery bypass grafting on hemorheological parameters.

Conditions during coronary artery bypass grafting (CABG) performed on beating heart (off-pump) are more physiological than using extracorporeal perfusion (on-pump). The present study aims to examine the hemorheological aspects of the two techniques. Blood samples were taken from patients undergoing on-pump (n = 25) and off-pump (n = 22) CABG, upon arrival to the operating theatre, after 20 and 40 minutes during the operation, after closing the thorax, on the 1st and 2nd postoperative days, and during the 2nd and 6th month control check-ups. Hematocrit (Hct), plasma and whole blood viscosity (PV, WBV; Hevimet 40 capillary viscometer), red blood cell (RBC) aggregation (Myrenne RBC aggregometer, LORCA) and deformability (LORCA, Carat FT-1 filtrometer), and platelet aggregation (Carat TX4 aggregometer) were determined. The morphology of red blood cells was investigated by scanning electron microscopy (SEM). Hct, PV, WBV and RBC aggregation decreased significantly during the early phase of the surgery, they started to recover during the postoperative period, and reached the baseline values by the 2nd and 6th month control check-ups. These parameters were significantly lower in samples taken after 20 and 40 minutes in the on-pump group. SEM showed rather damaged and malformed cells in case of on-pump surgery. Ektacytometry showed no significant difference, but RBC deformability was impaired during on-pump surgery when measured by filtrometry. The decrease in platelet aggregation was more pronounced by the end of surgery in case of on-pump technique. During CABG rheological parameters change less when using the off-pump method, and mechanical damage of RBCs are also smaller. The off-pump technique seems to be favorable from a hemorhelogical point of view.

Effect of cardiopulmonary bypass on cytokine network and myocardial cytokine production.

BACKGROUND: In addition to the well-investigated proinflammatory cytokine expression, there is an ever increasing interest in the field of anti-inflammatory response to cardiopulmonary bypass (CPB). Evidence suggests that myocardium serves as an important source of cytokines during reperfusion and application of CPB. The effect of coronary artery bypass graft (CABG) without CPB on myocardial cytokine production has not as yet been investigated. HYPOTHESIS: Cardiopulmonary bypass can cause long-term disturbance in pro- and anti-inflammatory cytokine balance, which may impede a patient's recovery following surgery. Therefore, the effect of CPB on the balance of the pro-/anti-inflammatory cytokines network and myocardial cytokine outflow was assessed throughout a longer period after surgery. METHODS: Twenty patients were scheduled for CABG with CPB and 10 had off-pump surgery. Blood samples were taken before, during, and over the first week following surgery. Coronary sinus blood samples were collected during surgery. The ratio of pro- and anti-inflammatory cytokines was calculated and the cytokine concentration of peripheral and coronary sinus blood were compared in both groups. RESULTS: Pro-/anti-inflammatory cytokine ratio decreased early after CPB followed by a delayed and marked increase. A more balanced ratio was present following off-pump surgery. Coronary sinus levels of certain cytokines exceeded the concentration of systemic blood in the course of CPB but not during off-pump operation. CONCLUSION: Patients show pro-inflammatory predominant cytokine balance at a later stage after CPB in contrast to those without CPB. The heart produces a remarkable amount of cytokines only in the course of surgery with CPB.

Expression of CD97 and adhesion molecules on circulating leukocytes in patients undergoing coronary artery bypass surgery.

OBJECTIVE: Leukocyte activation is thought to be responsible for the adverse effects and postoperative complications following cardiopulmonary bypass (CPB). A novel cell surface molecule, CD97, is a sensitive marker of leukocyte and primary lymphocyte activation. The present study aimed to determine the activation of different leukocyte subsets by comparing the expression of CD97 and adhesion molecules (CD11, CD18) in patients receiving coronary surgery with or without CPB. METHODS: 30 patients were enrolled and scheduled for coronary bypass surgery under CPB (20 patients, group A) and with off-pump (OP) operation (10 patients, group B). Blood samples were taken before and during surgery, and over the following first week. RESULTS: Here, we report an early decrease in CD97 expression of granulocytes (PMN) and monocytes (MC) followed by an intensive increase reaching the maximum on postoperative days 2 and 3 in patients operated with CPB. The rate of active CD97-positive lymphocytes showed a marked, gradual increase until postoperative day 3 and remained elevated up to day 7 after CPB. OP surgery resulted in moderate alteration in the presence of CD97 on PMN, MC and lymphocytes. The expression of adhesion molecules was similar to CD97 in all leukocyte subsets. CONCLUSION: The findings about CD97 expression suggest considerable leukocyte activation following coronary bypass with CPB compared to OP surgery. The collected data show that the lymphocytes are highly activated and involved in leukocyte sequestration after CPB. Moreover, the importance of CD97 in CPB-related inflammatory response can be stated.

[Experience with a minute ventilation sensing rate frequency adapted pacemaker]. / Tapasztalataink a percventiláció-változáson alapuló frekvencia adaptált pacemakerrel.

In the last two years 27 patients (mean age: 63.2 +/- 6.9 years) received Telectronics META MV pacemaker generators at the SZOTE. In 6 cases the generators were connected to atrial pacemaker electrodes, and in 21 cases to ventricular electrodes. To assess the characteristics of the rate responsive function exercise stress test was performed by 17 of these subjects. The authors give an account on the rate adaptive functions of these type pacemakers. The generator is an SSIR one. The rate responsive factor--i.e. the numerical characteristics of the pulse rate acceleration suggested by the pacemaker itself--was similar for atrial and ventricular electrodes.

The mechanism of blood pressure variability. Study in patients with fixed ventricular pacemaker rhythm.

BACKGROUND: Several studies have shown that heart rate variability plays an anti-oscillatory role in the regulation of blood pressure variability in humans. We tested whether systolic blood pressure variability in patients with a fixed ventricular pacemaker rhythm differs from that in patients with sinus rhythm. METHODS AND RESULTS: In 18 patients with a fixed ventricular pacemaker rhythm and in ten age-matched patients with sinus rhythm the systolic blood pressure oscillation and the low and high-frequency spectral components of systolic blood pressure were studied in the resting supine position during spontaneous breathing and during forced deep ventilation of 6 cycles.min-1. Patients with a pacemaker had a higher amplitude of systolic blood pressure oscillation than control subjects during spontaneous breathing (13.5 +/- 2.0 mmHg vs 6.4 +/- 1.6 mmHg, P = 0.035), and a slight but not significant difference also persisted during forced deep ventilation 19.0 +/- 2.3 mmHg vs 15.0 +/- 2.3 mmHg, P = 0.18). The increment in systolic blood pressure fluctuation from spontaneous breathing to forced deep ventilation was less marked in the pacemaker group than in the control subjects (40% vs 130%, P = 0.43). Although all the systolic blood pressure spectral components of the pacemaker patients were higher during both spontaneous breathing and forced deep ventilation, the differences between the two groups did not reach statistical significance. CONCLUSIONS: Our observations in patients with a fixed ventricular pacemaker rhythm suggest that the mechanical effects on the intrathoracic vessels and the consecutive stroke volume changes are responsible for respiration-related systolic blood pressure oscillation and reflex systolic blood pressure changes.

Secretion of phospholipase A2 induced by interactions of human platelets with monocytes.

Phospholipase A2 (PLA2) activity was found and measured in the cell-free supernatants of human mononuclear cells (monocytes and lymphocytes) cultured with platelets for 48 h at 37 degrees C. The relative molecular mass of purified, calcium-dependent PLA2 was 14 kD. The amount of PLA2 in the supernatants correlated positively with the number of monocytes and platelets in the cultures. Electron microscopically, direct cell-to-cell interactions of monocytes and platelets were observed. Cultivation of suspensions of human mononuclear cells with platelets in serum-free medium was found to be an efficient way to produce and purify human secretable PLA2. In the release of secretable PLA2 in peripheral blood, the interactions between platelets and monocytes may play a considerable role.

[Continuous non-invasive blood pressure monitoring in the diagnosis of pacemaker syndrome]. / Folyamatos, noninvazív vérnyomásmérés a pacemaker szindróma diagnózisában.

The drop in blood pressure coinciding with the atrioventricular dyssynchrony plays an important role in the genesis of pacemaker syndrome. The diagnosis is often based on continuous blood pressure recording. Formerly the continuous blood pressure monitoring could only be performed by invasive methods. The authors demonstrate the feasibility of a new non invasive continuous blood pressure recorder, the Finapres 2300, by presenting illustrative case reports. The authors recommend more widespread use of non invasive haemodynamic monitoring for the diagnosis of pacemaker syndrome.

Phagocytosis of autologous platelets by human neutrophil granulocytes.

The phenomenon that the autologous human platelets can be phagocytosed in vitro by neutrophils and monocytes of healthy human donors (being free of antiplatelet autoantibodies) was demonstrated earlier. In this study we have confirmed electron microscopically the phenomenon of phagocytosis. Besides, using flow cytometric analysis, we have shown that a possible way for the bridge-formation between the washed platelets and neutrophils can be the linkage via IgG + C3b complexes bound to the Fc receptors of platelets. This mechanism supposedly may play a role also in the clearance of platelets by peripheral phagocytes in vivo.

Epicardial ECG signals following global myocardial ischaemia.

Experiments were performed on 10 dog hearts undergone 15 to 90-minute normothermic arrests and 60-minute reperfusion in a special heart-lung model. The purpose of the experiments was to characterize the global ischaemic effects recorded on epicardial electrograms. The duration of QRS complexes and of RR intervals, the integral of ST segment shifts (sigma ST), the number of points showed ST segment displacements (NoST) and the ST segment isopotential map obtained by computer control were evaluated. Only a minor ST segment deviation, a small increase in duration of QRS complexes and of RR intervals with bradycardia and a tendency to electrical stability were found after global ischaemic influences. These observations indicate that pathological electrical manifestations occurring after a global ischaemia are less serious than those occurring after a focal ischaemia.