Acute respiratory distress syndrome (ARDS) is severe medicalcondition
occurring in critically ill patients and with mortality of 33-52 % is one of the leading causes of death in critically ill patients. To better understand pathophysiology of ARDS and to verify novel therapeutical approaches a reliable animal model is needed. Therefore we have developed modified
lavage model of ARDS in the pig. After premedication (ketamine and midazolam)35 healthy pigs were anesthetized (propofol, midazolam,
morphin, pipecuronium) and orotracheally intubated and ventilated. Primary
ARDS was induced by repeated cycles of lunglavage with a detergent Triton X100 diluted in saline (0.03 %) heated to 37 °C preceded by pre
-oxygenation with 100 % O2. Single cycle included two subsequent lavages
followed by detergent suction. Eachcyclewas followed by hemodynamic
andventilation stabilization for approx. 15 min, with eventualadministration of vasopressors according to an arterial bloodpressure. The lavage procedure
was repeated until the paO2/FiO2index after stabilization remained below 100 at PEEP 5 cm H2O. In 33 pigs we have achieved the desired degree
of severe ARDS(PaO2/FiO2<100). Typical number of lavages was 2-3 (min. 1,max.5). Hemodynamictolerance and the need for vasopressors
were strongly individual. In remainingtwo animalsan unmanageable hypotension developed. For other subjects theexperimental ARDS stability was good and allowed reliablemeasurement for more than 10 h. The
present model of theARDS is clinically relevant and thus it is suitable for further research of the pathophysiology and management of this serious
medical condition.
Some antidepressant drugs, especially tricyclic ones - (TCA), have cardiovascular side effects. To compare the effects of antidepressant drugs, the electrocardiogram (ECG), vectorcardiogram (VCG), and body surface maps (BSM) were recorded in psychiatric patients without cardiovascular diseases treated by a) TCA amitriptyline or dosulepin (daily dose 50-200 mg, 22 patients), b) lithium (serum level 0.66±0.08 meq/1, 21 patients), c) selective serotonine reuptake inhibitor citalopram (daily doses 20-60 mg, 30 patients), and in 23 control patients. In the TCA-treated patients, the heart rate was increased, QT and RR intervals shortened (p<0.01, antimuscarinic effect). This was not observed in lithium- and citalopram-treated patients. All antidepressants decreased the absolute maximum values of depolarization isointegral maps, lithium and TCA reduced the initial and citalopram the later phase of depolarization. Citalopram slightly diminished the amplitude of the R wave. The results confirm the antimuscarinic effects of TCA in therapeutic doses and specify the intraventricular effects of antidepressants.
Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a method used for the treatment most severe cases of decompensated heart failure. The purpose of this study was to evaluate the risk of the formation of microembolisms during VA-ECMO-based therapy. Heart failure was induced with simultaneous detection of microembolisms and the measurement of blood flow rate in the common carotid artery (CCA) without VA-ECMO (0 l/min) and at the VA-ECMO blood flow rate of 1, 2, 3 and 4 l/min. If embolisms for VA-ECMO 0 l/min and the individual regimes for VA-ECMO 1, 2, 3, 4 l/min are compared, a higher VA-ECMO flow rate is accompanied by a higher number of
microembolisms. The final microembolism value at 16 min was for the VA-ECMO flow rate of 0 l/min 0.0 (0, 1), VA-ECMO l/min 7.5 (4, 19), VA-ECMO 2 l/min 12.5 (4, 26), VA-ECMO 3 l/min, 21.0 (18, 57) and VA-ECMO 4 l/min, 27.5 (21, 64). Such a comparison is statistically significant if VA-ECMO 0 vs. 4 l/min p<0.0001, 0 vs. 3 l/min p<0.01 and 1 vs. 4 l/min p<0.01 are compared. The results confirm that high VA-ECMO flow rates pose a risk with regards to the formation of a significantly higher number of microemboli in the blood circulation and that an increase in blood flow rates in the CCA corresponds to changes in the VA-ECMO flow rates.
Cardiac resynchronization therapy (CRT) has proven efficacious in reducing or even eliminating cardiac dyssynchrony and thus improving heart failure symptoms. However, quantification of mechanical dyssynchrony is still difficult and identification of CRT candidates is currently based just on the morphology and width of the QRS complex. As standard 12-lead ECG brings only limited information about the pattern of ventricular activation, we aimed to study changes produced by different pacing modes on the body surface potential maps (BSPM). Total of 12 CRT recipients with symptomatic heart failure (NYHA II-IV), sinus rhythm and QRS width ≥120 ms and 12 healthy controls were studied. Mapping system Biosemi (123 unipolar electrodes) was used for BSPM acquisition. Maximum QRS duration, longest and shortest activation times (ATmax and ATmin) and dispersion of QT interval (QTd) were measured and/or calculated during spontaneous rhythm, single-site right- and left-ventricular pacing and biventricular pacing with ECHO-optimized AV delay. Moreover we studied the impact of CRT on the locations of the early and late activated regions of the heart. The average values during the spontaneous rhythm in the group of patients with dyssynchrony (QRS 140.5±10.6 ms, ATmax 128.1±10.1 ms, ATmin 31.8±6.7 ms and QTd 104.3±24.7 ms) significantly
differed from those measured in the control group (QRS 93.0±10.0 ms, ATmax 79.1±3.2 ms, ATmin 24.4±1.6 ms and QTd 43.6±10.7 ms). Right ventricular pacing (RVP) improved significantly only ATmax [111.2±10.6 ms (p<0.05)] but no other measured parameters. Left ventricular pacing (LVP) succeeded in improvement of all parameters [QRS 105.1±8.0 ms (p<0.01), ATmax 103.7±7.1 ms (p<0.01), ATmin 20.2±3.7 ms (p<0.01) and QTd 52.0±9.4 ms (p<0.01)]. Biventricular pacing (BVP) showed also a beneficial effect in all parameters [QRS 121.3±8.9 ms (p<0.05), ATmax 114.3±8.2 ms (p<0.05), ATmin 22.0±4.1 ms (p<0.01) and QTd 49.8±10.0 ms (p<0.01)]. Our results proved beneficial outcome of LVP and BVP in evaluated parameters (what seems to be important particularly in the case of activation times) and revealed a complete return of activation
times to normal distribution when using these CRT modalities.
The authors describe the results of intra-operative hemodynamic monitoring during laparoscopic cholecystectomy in patients with ischemic left ventricular dysfunction and with significant aortic stenosis. The results in the groups composed of 13 and 12 patients were compared with the findings in 10 young, non-obese, non-smokers without significant cardiovascular history and with normal findings during resting transthoracic echocardiography. Monitoring itself was conducted using transesophageal echocardiography 1) after the induction of anesthesia, 2) after the induction of capnoperitoneum, and 3) after setting the operative anti-Trendelenburg position. The measurements were performed at least in triplicate and the results were processed using ANOVA test. Significant differences were identified in the time course patterns of heart rate, mean arterial pressure, dual product (pressure-rate-product), and cardiac output. In terms of pathophysiology, we believe that the most important achievement was the identification of different time course patterns of individual parameters in the respective groups. The results in the group of patients with aortic stenosis were based particularly on the different time course of the mean arterial pressure, while the results in patients with ischemic disease were more dependent on the time course of the heart rate. Very ineteresting is a drop of peripheral vascular resistance after positioning of these patients which could be explained only partially by a beta-blocking or ACEI medication. In clinical terms, the most important finding was probably that no complications occurred in the entire group of 35 patients, of which 25 suffered from severe organic cardiopathies.
Cardiac resynchronization therapy (CRT) has proven efficacious
in the treatment of patients with heart failure and
dyssynchronous activation. Currently, we select suitable CRT
candidates based on the QRS complex duration (QRSd) and
morphology with left bundle branch block being the optimal
substrate for resynchronization. To improve CRT response rates,
recommendations emphasize attention to electrical parameters
both before implant and after it. Therefore, we decided to study
activation times before and after CRT on the body surface
potential maps (BSPM) and to compare thus obtained results with
data from electroanatomical mapping using the CARTO system.
Total of 21 CRT recipients with symptomatic heart failure (NYHA
II-IV), sinus rhythm, and QRSd ≥150 ms and 7 healthy controls
were studied. The maximum QRSd and the longest and shortest
activation times (ATmax and ATmin) were set in the BSPM maps
and their locations on the chest were compared with CARTO
derived time interval and site of the latest (LATmax) and earliest
(LATmin) ventricular activation. In CRT patients, all these
parameters were measured during both spontaneous rhythm and
biventricular pacing (BVP) and compared with the findings during
the spontaneous sinus rhythm in the healthy controls. QRSd was
169.7±12.1 ms during spontaneous rhythm in the CRT group and
104.3±10.2 ms after CRT (p<0.01). In the control group the
QRSd was significantly shorter: 95.1±5.6 ms (p<0.01). There
was a good correlation between LATmin(CARTO) and
ATmin(BSPM). Both LATmin and ATmin were shorter in the
control group (LATmin(CARTO) 24.8±7.1 ms and ATmin(BSPM)
29.6±11.3 ms, NS) than in CRT group (LATmin(CARTO) was
48.1±6.8 ms and ATmin(BSPM) 51.6±10.1 ms, NS). BVP
produced shortening compared to the spontaneous rhythm of
CRT recipients (LATmin(CARTO) 31.6±5.3 ms and ATmin(BSPM)
35.2±12.6 ms; p<0.01 spontaneous rhythm versus BVP). ATmax
exhibited greater differences between both methods with higher
values in BSPM: in the control group LATmax(CARTO) was
72.0±4.1 ms and ATmax (BSPM) 92.5±9.4 ms (p<0.01), in the
CRT candidates LATmax(CARTO) reached only 106.1±6.8 ms
whereas ATmax(BSPM) 146.0±12.1 ms (p<0.05), and BVP paced
rhythm in CRT group produced improvement with
LATmax(CARTO) 92.2±7.1 ms and ATmax(BSPM) 130.9±11.0 ms
(p<0.01 before and during BVP). With regard to the propagation
of ATmin and ATmax on the body surface, earliest activation
projected most often frontally in all 3 groups, whereas projection
of ATmax on the body surface was more variable. Our results
suggest that compared to invasive electroanatomical mapping
BSPM reflects well time of the earliest activation, however
provides longer time-intervals for sites of late activation.
Projection of both early and late activated regions of the heart on
the body surface is more variable than expected, very likely due
to changed LV geometry and interposed tissues between the
heart and superficial ECG electrode.
The aim of the study was to detect the changes of QT dispersion (QTd) due to cardiotoxicity of tricyclic antidepressant dosulepin. Electrocardiographic and vectorcardiographic recordings were obtained using Cardiag 112.2 diagnostic system from 28 psychiatric outpatients treated with prophylactic doses of dosulepin and compared to those obtained from 37 healthy volunteers. From these recordings following parameters were evaluated: QTd, spatial QRS-STT angle and amplitude of T-wave. The acquired data were correlated with the dosulepin plasma levels using Spearman´s rank order correlation test. The average QTd (±S.D.) in the dosulepin group was significantly higher (70±21 ms) than that in the control group (34±12 ms) (P<0.001). Moreover, the correlation between QTd and the dosulepin plasma levels was highly significant (r = 0.7871, P<0.001). Similar results were obtained when QTc dispersion was used. On the contrary, the QRS-STT space angle did not correlate with the dosulepin plasma levels. Furthermore, the T-wave amplitude was not significantly correlated to the QT-interval. Thus we can conclude that the QT dispersion could be used as a simple marker of the dosulepin effect on the myocardium.
Mew possibilities of quantitative evaluation of body surface potential mapping were studied in 78 patients with ischaemic heart disease. Integral maps of the Q wave, QRS and ST-T intervals were plotted and isochronous maps of ventricular activation time and maps of asynchronous potential minima of the Q wave were determined. Minimum and maximum potential values and their time relations were evaluated in the maps. Left ventricular contraction abnormality detected by left ventricular angiography was determined by a point score and expressed as an index of asynergy. The number of coronary artery branches with significant narrowing was assessed and the extent of coronary artery damage was evaluated by an arbitrary defined index. Using quantitative parameters from the maps, multiple stepwise linear regression was performed. The relationship between map parameters and index of asynergy corresponded to multiple correlation coefficient r=0.69 (p=0.01) in the whole group of patients. In the group of patients with left ventricular contraction abnormality the relationship between these parameters was found to be r=0.87 (p=0.01). The relationship between map parameters and the number of coronary artery branches with significant stenosis was r=0.60 (p=0.01) in the group of patients with positive coronary angiography. In the same group of patients the relationship between map parameters and the index evaluating coronary artery damage was equal to r=0.63 (p=0.01). The data obtained from body surface integral maps enable to quantify cardiac ischaemic damage.
The aim of our study was to assess if repolarization BSPM were able to evaluate the site, size and severity of chronic ischaemic damages and if BSPM were in any way related to the regional attenuation of myocardial contractility or to the site of coronary artery occlusion. The BSPM were obtained from 69 patients suffering from coronary artery disease confirmed by coronarography, with at least 75 % occlusion of at least one coronary artery. According to the site of single occlusion, or a combination of the sites of multiple occlusions, the patients were divided into 6 subgroups. According to the region of attenuated kinetics the same group of 69 patients was also divided into other 6 subgroups. As in the polarity distribution there was only a limited accordance in BSPM with coronarographie and échocardiographie Findings, in the localization of extreme values there were very important specific changes in patients with normal kinetics as determined by both contrast ventriculography and two-dimensional echocardiography. The repolarization maps can distinguish patients with coronary artery disease and normal echocardiography from healthy persons with a sensitivity of 85 % and a specificity of 65 % in the case of the isoareal map from the ST segment (R1AM) and 90 % and 85 %, respectively, in the case of the isointegral map from the whole ST-T segments (R1IM).