Biomedical subjects

W A Stertmann

Publications and source records attributed to W A Stertmann.

At least 19 recordsLinked to original sources

PubMed2005

Post-mortem evaluation of 415 pacemakers: in situ measurements and bench tests.

AIM: The hypothesis was that there is more undetected dysfunction of implanted pacemaker systems than that detected and corrected. This prompted a research project (sponsored by the German Research Foundation) to detect pacemaker abnormalities and evaluate their complications for patients, thus, proving or disproving the hypothesis. METHODS AND RESULTS: Four hundred and fifteen pacemakers of deceased patients were analyzed assessing their functionality by in situ measurements and bench tests including five measurements and one telemetric interrogation. Results were divided into four categories and statistically evaluated. Life-threatening abnormalities were found in 3.8%, potentially life-threatening in 3.7%, probably symptomatic, divided into atrial and ventricular problems, 13.3% and 2.8%, respectively, and premature exhaustion in 1.2%. Three of 179 bipolar ventricular leads and 2 of 131 bipolar atrial leads had insulation defects corresponding to 1.7% and 1.5%, respectively. The bipolar complication rate was 2.8 times higher than unipolar. CONCLUSION: The pacemaker patients investigated, living 4 years with their pacemaker on average, had a post-mortem evaluated complication rate of the category "life-threatening" of 3.8%. This result corresponds to an annual complication rate of 0.94% compared with a rate of only 0.39% in an earlier investigation.

Aged↗

PubMed2003

[Penetrating knife injury of the heart. Emergency management and definitive treatment: case report and review of the literature].

The outcome of patients with penetrating heart injuries depends to a great extent on aggressive primary care and fast transport to the closest appropriate trauma center. There, after confirming the diagnosis, the injured victim has to be transferred without any delay to the operating room where the penetrating injury can be dealt with. The importance of resolute emergency management is shown based on a case presentation and a review of the current literature. The employment of extracorporal circulation (heart-lung machine) is rather subordinate in the primary care of these patients.

Adult↗

PubMed2000

Efficacy of single lead VDD pacing in patients with impaired and normal left ventricular function.

Atrial synchronous ventricular pacing seems to be the best pacing mode for patients with advanced AV block and impaired LV function. The long-term follow-up of single lead VDD pacing was studied in 33 patients with impaired LV function and compared to 42 patients with normal LV function. All patients received the same VDD lead and VDDR pacemaker. The lead model with 13-cm AV spacing between the atrial and ventricular electrode was implanted in 89% of the patients. Follow-ups were 1, 3, 6, and 12 months after implantation. The percentage of atrial sensing and the P wave amplitude were determined at each follow-up. Minimal P wave amplitude at implantation was 2.0 +/- 1.4 mV in patients with impaired and 1.7 +/- 0.9 mV with normal LV function (not significant). At the 12-month follow-up, 33 patients with normal and 23 patients with depressed LV function remained paced in the VDD mode. The remaining patients died in five (impaired LV function) and seven cases (normal LV function) or their pacemakers were programmed to the VVI/VVIR pacing mode in four (impaired LV function) and three cases (normal LV function). P wave amplitude did not differ in the two groups (e.g., at month 12: impaired: 1.17 +/- 0.42 mV; normal: 1.09 +/- 0.49 mV). The atrial sensitivity was programmed in most patients to sensitive settings with no differences between the two groups (e.g., at month 12: impaired: 0.13 +/- 0.06 mV; normal: 0.13 +/- 0.05 mV). The diagnostic counters indicated nearly permanent atrial sensing (e.g., at month 12: impaired: 99.3 +/- 2.2%; normal: 99.0 +/- 1.0 mV). In conclusions, single lead VDD pacing restored AV synchronous ventricular pacing in patients with normal and with impaired LV function indicating that it could be an alternative to DDD pacemakers, but not to dual-chamber pacing.

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PubMed1998

[The intraoperative measured stimulation impedance of pacemaker electrodes is not a predictor for their longevity].

UNLABELLED: As pacing impedance is inversely related to pacing current, the increase of pacing impedance additionally decreases pacing current. Whether the impedance measurement at implantation predicts the outcome during follow-up, was studied in 87 patients who received the VDD-single lead UniPass 425 connected to the pacemaker Unity (Sulzer Intermedics). The impedance changes between implantation and 6 months follow-up were assessed for each patient. Similar impedance values were defined, if the two measurements were within a range < or = -100 to +100 omega. Six-months impedance was lower or higher compared to implantation, if the difference exceeded > -100 or > +100 omega. At implantation, impedance was 535 +/- 98 omega (range: 333-811 omega) and significantly increased to 604 +/- 160 omega (range: 361-1150 omega) after 6 months. Mean difference between the two measurements was 69 +/- 162 omega (range: -336 bis + 560 omega). Similar impedance had 43 (implantation: 527 +/- 75 omega, 6 months: 531 +/- 87 omega), lower values 11 (implantation: 660 +/- 83 omega, 6 months: 494 +/- 73 omega) and higher values 33 patients (implantation: 503 +/- 99 omega, 6 months: 735 +/- 168 omega). Compared to the patients with similar impedance patients with lower impedance had a significantly higher impedance values at implantation. CONCLUSIONS: Pacing impedance increased significantly within 6 months after implantation. Pacing impedance changed > 100 omega in 51% of the patients. The long-term follow-up of pacing impedance can be predicted generally, but not for the individual patient.

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PubMed1997

[The effect of a lower stimulation frequency on the AV synchronicity of VDD pacemakers].

BACKGROUND AND OBJECTIVE: Implantation of a VDD pacemaker (ventricular pacing; dual sensing [atrial and ventricular]; dual response [triggered + inhibited]) together with a single VDD electrode catheter restores synchronous AV ventricular stimulation in patients with higher-grade AV block and intact sinus function. If higher-frequency stimulation occurs it may be a sign of pacemaker malfunction or of inadequate pacemaker programming. This study was undertaken to determine, at first follow-up examination, in how many patients with a VDD pacemaker VVI stimulation occurred more than 5% of the time; how such patients differed from those with 5% or fewer VVI stimulations; and whether a changed program reduced the proportion of VVI stimulations. PATIENTS AND METHODS: 67 consecutive patients were tested 1 to 3 months after implantation of the Unity VDD pacemaker (Sulzer Intermedics). The frequency of VVI stimulations was determined via a diagnostic pacemaker memory store. After intermediate analysis, programming was optimized and the patients then re-tested 12 months after the initial implantation. RESULTS: At the first follow-up examination 54 patients had VVI stimulations of < or = 5% (0.5 +/- 0.9%) and 13 had > 5% of the time (19.8 +/- 10.7%). The two groups differed significantly from one another in their lower intervention frequency (< or = 5% VVI stimulations: 47 +/- 6/min; > 5% VVI stimulations: 58 +/- 5/min). In particular, the pacemakers in patients with > 5% VVI stimulations had been significantly more often programmed to values of > 50/min. As a result, the pacemakers of these patients were reprogrammed to a lower frequency. A year after implantation there was no longer any difference in the lower intervention frequency, 44 +/- 4/min, between patients with initially > 5% VVI stimulations and those with initially < or = 5% stimulations. At the same time, the proportion of VVI stimulations fell to 4 +/- 6%, with 67% of patients having AV synchronicity of > 95%. INTERPRETATION: At first follow-up, patients with > 5% VVI stimulations differed from those with < or = 5% stimulations with regard to an increased lower intervention frequency. In most of these patients the proportion of AV stimulations was increased to > 95% by reducing the lower intervention frequency to < or = 50/min.

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PubMed1997

[Microembolizatoins during heart surgery under extracorporeal circulation].

OBJECTIVE: By means of transcranial Doppler sonography (TCD), microembolic signals (MES) representing embolic events can be registered during cardiac surgery and extracorporeal circulation in a considerable number of patients. We conducted the present study to determine the neuro-psychiatric consequences of MES. METHODS: 25 patients scheduled for elective aorto-coronary bypass grafting (ACBG; n = 10) or aortic valve replacement (AVR; n = 15) were studied pre- and postoperatively with neuropsychiatric testing. Results were related to the number of MES noted intraoperatively. In addition, we registered the intraoperative changes of middle cerebral artery blood flow velocity, mean arterial pressure, arterial blood gases, haemoglobin and haematocrit. Statistics included t-test, two-way analysis of variance, Mann-Whitney-U-test and Spearman correlation with p < 0.05 considered significant. RESULTS: Regarding demographic data and intraoperative parameters, both study groups (ACBG vs. AVR) were comparable except for age. AVR patients showed significantly more MES than those undergoing ACBG (p < 0.012) which was most pronounced in the late state of surgery (aortic clamp off; p < 0.0003). However, MES counts did not correlate with neuropsychiatric test results. CONCLUSIONS: In contrast to recent reports, we were unable to show a deterioration of postoperative neuropsychiatric state related to high intraoperative MES count in our patients. Future TCD studies should focus on the differentiation between gaseous emboli and particles even in the clinical setting, as the latter may well play a major role for the development of cerebral dysfunction following cardiac surgery and extracorporeal circulation.

Analysis of Variance↗

PubMed1995

Circulating adhesion molecules in cardiac operations: influence of high-dose aprotinin.

Cardiac operations using cardiopulmonary bypass (CPB) are associated with a systemic inflammatory response most likely attributable to the release of various inflammatory mediators and activation of complement or coagulation cascade. In addition, (circulating) adhesion molecules, such as endothelial leukocyte adhesion molecule (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1), appear to be of central importance in the CPB-related inflammatory process. In this situation, antiproteases, such as aprotinin, may help to prevent damage of endothelial integrity. In a prospective study, 40 consecutive patients undergoing elective cardiac operation were randomly divided into two groups (with 20 patients in each group): in group 1 "high-dose" aprotinin was used (2 million IU of aprotinin before CPB, 500,000 IU/h until end of operation, 2 million IU added to the prime) (with aprotinin), and in group 2 no aprotinin was given (without aprotinin). Circulating adhesion molecules (cICAM-1, cELAM-1, and cVCAM-1) were measured from arterial blood samples using ELISA after induction of anesthesia (baseline), during CPB, at the end of the operation, 5 hours after CPB, and on the first postoperative day. The two groups were comparable concerning their biometric profile and CPB data. Baseline values of circulating adhesion molecules were within normal range and similar in both groups. During CPB, hemodilution resulted in a decrease in all circulating adhesion molecules. On the first postoperative day, cICAM-1 (with aprotinin, 215 +/- 32 ng/mL; without aprotinin, 230 +/- 40 ng/mL) and cELAM-1 (with aprotinin, 28 +/- 6 ng/mL; without aprotinin, 31 +/- 6 ng/mL) returned to baseline values.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

Endothelial-related coagulation in cardiac surgery.

The endothelium appears to play an important role in the regulation of intravascular coagulation. Thrombomodulin is one of the anticoagulant substances that is expressed by endothelial cells. The influence of age and illness on the thrombomodulin-protein C system was studied prospectively in 80 cardiac surgery patients. Patients > 70 yr old (n = 20) were compared with patients < 50 yr (n = 20) (group I), and patients undergoing a simple cardiac procedure (n = 20) were compared with patients scheduled for complex surgery (n = 20) (group II). Thrombomodulin (normal < 40 ng ml-1), protein C and (free) protein S plasma concentrations were measured by enzyme-linked immunosorbent assays (ELISA) after induction of anaesthesia (baseline values), during and after cardiopulmonary bypass (CPB), at the end of surgery, 5 h after CPB and on the first day after operation. Blood loss and use of homologous blood and blood products were significantly greater in patients > 70 yr and in those undergoing complex surgery. At baseline, thrombomodulin concentration was increased in patients undergoing complex surgery (mean 52 (sd 9) ng ml-1). After bypass and after operation, thrombomodulin increased most in patients > 70 yr (from 40 (8) to 78 (10) ng ml-1) and in those patients who underwent complex cardiac operations (from 52 (8) to 79 (10 ng ml-1) (P < 0.05). Changes in protein C and protein S concentrations were similar in all groups. On the first day after operation only, protein C concentrations were reduced in patients > 70 yr and in patients who underwent complex cardiac surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Cerebrovascular carbon dioxide reactivity in carotid artery disease. Relation to intraoperative cerebral monitoring results in 100 carotid endarterectomies.

BACKGROUND: In patients with carotid artery disease, poor intracerebral collateralization is reflected by impaired cerebrovascular reactivity to carbon dioxide inhalation, which will improve after endarterectomy. The relationship between preoperative reactivity to carbon dioxide using transcranial Doppler sonography (TCD) and intraoperative changes of somatosensory evoked potentials (SEP) and TCD parameters were investigated. METHODS: In 94 patients, preoperative carbon dioxide reactivity was examined and defined impaired if mean blood flow velocity in the middle cerebral artery (Vm-MCA) increased less than 1.5% mmHg during carbon dioxide challenge. Patients then underwent 100 carotid operations under general anesthesia with both SEP and TCD monitoring. Shunts were placed if SEP amplitude decreased to less then 50% of control or central conduction time increased by 20% after clamping (critical SEP changes). TCD changes were defined as critical in case of a postclamping/preclamping Vm-MCA ratio < or = 0.4. The incidence of critical SEP and TCD changes was compared to preoperative carbon dioxide testing using Fisher's exact test with P < 0.05 considered significant. Postoperatively, neurologic state and carbon dioxide responsiveness were re-examined. RESULTS: Twelve patients showed impaired preoperative carbon dioxide reactivity on the side of operation, which improved markedly after surgery. The incidence of critical SEP changes in these cases (8.3%) was not significantly different from that in the remaining patients (14.8%). Critical SEP changes were significantly correlated with critical TCD changes (P < 0.0001). CONCLUSIONS: Patients with poor carbon dioxide reactivity (preoperative TCD testing) did not have an increased risk of cerebral ischemia during carotid surgery, as assessed by intraoperative SEP recording.

Blood Flow Velocity↗

PubMed1995

The effect of the anticoagulation regimen on endothelial-related coagulation in cardiac surgery patients.

Heparin is still the most commonly used anticoagulant in cardiac surgery necessitating cardiopulmonary bypass. In recent years, endothelial-related coagulation (e.g. thrombomodulin/protein C-system) has enlarged our knowledge of the regulation of haemostasis. In a controlled randomised study, the influence of different regimens of anticoagulation on the thrombomodulin/protein C-system was studied. Sixty patients undergoing elective coronary artery bypass grafting were randomly allocated into four groups (n = 15) to receive: 300 IU.kg-1 of heparin before bypass; 600 IU.kg-1 of heparin; 300 IU.kg-1 of heparin as bolus followed by a continuous infusion of 10 000 IU.h-1 until the end of bypass; or 600 IU.kg-1 of heparin plus 'high dose' aprotinin (2 million IU of aprotinin before bypass, 500 000 IU.h-1 until the end of the operation and 2 million IU added to the bypass pump prime). Grouping was blinded for the surgeon and the anaesthetist. Plasma concentrations of thrombomodulin, protein C and (free) protein S as well as thrombin/antithrombin III were measured by enzyme-linked-immunosorbent assays after induction of anaesthesia, during and after bypass, at the end of surgery, 5 h after bypass, and on the first postoperative day. Activated clotting time was significantly longer during bypass in group 2 (566 (60)s) and group 4 (655 (59)s), whereas standard coagulation parameters showed no differences between the four groups. Blood loss and use of homologous blood and blood products were highest in groups 2 and 3. Thrombomodulin plasma levels were similar (and normal) at baseline (< 40 ng.l-1), decreased during bypass and reached baseline values postoperatively without showing significant group differences. Protein C did not show any differences among the groups within the investigation period. 'Free' protein S plasma levels were most reduced in group 1 (from 68 (8)% to 48 (9)% after bypass). Thrombin/antithrombin III plasma concentrations increased most in groups 1 (to 69 (14) micrograms.l-1 after bypass) and 2 (to 48 (7) micrograms.l-1 after bypass), whereas they remained significantly lower in groups 3 and 4. The thrombomodulin/protein C-system was not significantly influenced by the regimen of anticoagulation. Administration of 'high-dose' heparin was associated with the highest blood loss, which could not be related to endothelial-associated coagulation.

Aged↗

PubMed1994

RETRACTED: Does aprotinin influence endothelial-associated coagulation in cardiac surgery?

Aprotinin has been reported to reduce bleeding in cardiac surgery patients. Its mechanisms of action on coagulation have not been fully elucidated. In a prospectively randomized study of 40 patients undergoing elective aortocoronary bypass grafting, the influence of high-dose aprotinin (2 million IU of aprotinin before CPB, 500,000 IU/h until the end of operation, 2 million IU added to the prime) (N = 20) on endothelial-related coagulation was compared to a nontreated control group (N = 20). Thrombomodulin (TM), protein C and (free) protein S as well as thrombin/antithrombin-III (TAT) plasma concentrations were measured by enzyme-linked immunosorbent assays (ELISA) before the aprotinin infusion, before cardiopulmonary bypass (CPB), during CPB and after CPB, at the end of surgery, 5 hours after CPB, and on the first postoperative day. All standard coagulation parameters (AT-III and fibrinogen plasma levels, platelet count, partial thromboplastin time) did not differ between the two groups. At baseline, TM plasma levels were within the normal range (< 40 ng/mL) and similar in both groups. During CPB, TM plasma concentrations decreased similarly in both groups (aprotinin: 18 +/- 6 ng/mL, control: 17 +/- 7 ng/mL) followed by a comparable increase in the postbypass period until the first postoperative day (aprotinin: 60 +/- 10 ng/mL, control: 53 +/- 11 ng/mL). Protein C and (free) protein S plasma levels also showed no differences between the two groups. On the first postoperative day, baseline values for protein C and protein S had not yet been reached.(ABSTRACT TRUNCATED AT 250 WORDS)

Antithrombin III↗

PubMed1994

RETRACTED: Volume loading with hypertonic saline solution: endocrinologic and circulatory responses.

Hypertonic saline solution appears to be an attractive method of volume expansion. In 45 patients undergoing elective aorto-coronary bypass grafting, endocrinologic and circulatory responses to volume loading with hypertonic saline solution prepared in low molecular weight (MW) hydroxyethyl starch (HES) solution (72 g/L NaCl, HES concentration: 6%; MW: 200,000 D; degree of substitution [DS]: 0.5) (HS-HES) was compared randomly to patients who had received low molecular weight HES solution (LMW-HES). A group of patients without volume loading served as a control. Volume was infused to double the low pulmonary capillary wedge pressure (PCWP < 5 mmHg) after induction of anesthesia. Plasma levels of atrial natriuretic peptide (ANP), endothelin, vasopressin, and catecholamines were measured before, during, and after cardiopulmonary bypass (CPB) until the first postoperative day. In addition to systemic circulatory changes, capillary skin blood flow was measured by laser Doppler flowmetry. ANP plasma concentration increased in both volume groups (HS-HES: +79%; HES: +32%), whereas it decreased in the control (-20%). Infusion of HS-HES resulted in an increase in plasma endothelin concentration before and after CPB (from 3 to 6 pg/mL). Five hours after CPB, both treatment groups had higher endothelin plasma concentrations than the control patients (P < 0.05). Epinephrine and norepinephrine plasma levels increased most markedly in the control patients and were highest in the postbypass period in these patients. CI increased most after infusion of HS-HES (+65%) (P < 0.05). In the postbypass period, CI remained significantly higher in both volume groups than in the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Natriuretic Factor↗

PubMed1994

Influence of different anticoagulation regimens on platelet function during cardiac surgery.

Qualitative platelet defects are of great importance as a cause of bleeding in cardiac surgery. We have studied the effects of different anticoagulation regimens on platelet function in 60 patients undergoing elective aorto-coronary bypass grafting with cardiopulmonary bypass (CPB). Patients were allocated randomly to four groups (each group n = 15) to receive either: bovine heparin 300 u. kg-1 (standard); heparin 300 u. kg-1 followed by a continuous infusion of 10,000 u. kg-1 until the end of CPB; heparin 600 u. kg-1; or heparin 600 u. kg-1 in addition to high-dose aprotinin 2 million iu before CPB, 500,000 iu h-1 until the end of operation and 2 million iu added to the prime. Platelet function was evaluated by aggregometry (turbidometric technique) using adenosine triphosphate (ADP) 2.0 mumol litre-1, collagen 4 microliters ml-1, adrenaline 25 mumol litre-1 and saline solution (control) as inducers. Both maximum aggregation and maximum gradient of aggregation were measured in arterial blood samples before, during and after CPB until the first day after operation. Mean total dose of heparin given in groups 2, 3 and 4 was more than 50,000 u. and differed significantly from that of group 1 (28,150 (SD 4700)u.). Platelet aggregation variables were most depressed during CPB and until the end of surgery in groups 2 and 3 (maximum aggregation - 54% to - 75% of baseline values). In the postoperative period, platelet function recovered but did not completely reach baseline values in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Isolated circulatory response to intravenous administration of the ACE inhibitor enalaprilat.

The isolated vascular effects of intravenous administration of the angiotensin converting enzyme (ACE) inhibitor enalaprilat were investigated. Thirty male patients undergoing cardiopulmonary bypass (CPB) were studied. According to a randomized sequence, 0.04 mg kg-1 enalaprilat (low-dose, n = 10), 0.08 mg kg-1 (high-dose, n = 10) enalaprilat or saline solution as placebo (control group, n = 10) was given as an i.v. bolus during CPB. Changes in mean arterial pressure (MAP) and venous reservoir (RV) of the extracorporeal circulation were studied as indices of arterial resistance and venous capacitance. Mean arterial blood pressure (MAP) and peripheral vascular resistance (SVR) were significantly more reduced in the high-dose enalaprilat group (MAP: -36 mm Hg after 9 min; SVR: -836 dyn s cm-5) than in the low-dose group (MAP: -13 mm Hg after 10 min). Volume of the reservoir (RV) decreased in both enalaprilat treated groups indicating additional (dose-dependent) venous pooling effects of the substance (low-dose: -300 ml; high-dose: -520 ml; control group: -100 ml). Skin capillary blood flow measured by laser Doppler flowmetry (LDF) increased after injection of 0.04 mg kg-1 enalaprilat, whereas it decreased significantly when MAP fell markedly in patients treated with high-dose enalaprilat. I.v. enalaprilat had dose-dependent vasodilating properties in the arterial and venous vessel system indicating reduction in pre- and afterload. Microcirculation in both enalaprilat treated groups improved as long as reduction in blood pressure was not limited.

Blood Pressure↗

PubMed1994

Cold or warm start of cardiopulmonary bypass--influence on microcirculatory blood flow.

In a randomized study of 30 patients undergoing elective aortocoronary bypass grafting, either cold start of cardiopulmonary bypass (CPB) (prime: room temperature [approximately 20 degrees C], n = 15) or normothermic start of CPB (prime: warmed up to the patients' blood temperature, n = 15) were performed. After warm start, CPB was continued using almost normothermia (lowest nasopharyngeal temperature: 35.8 +/- 0.4 degrees C), after cold start hypothermia was used (lowest nasopharyngeal temperature: 28.8 +/- 0.2 degrees C). Changes in microcirculatory perfusion were assessed by measuring skin capillary blood flow at the patient's forearm and forehead using laser Doppler technique. Laser Doppler flow (LDF) was continuously monitored before onset of CPB (= baseline values), 30 seconds, one, five, 10, 15 and 20 minutes after start of CPB. Mean arterial blood pressure (MAP) and systemic vascular resistance (SVR) were reduced by CPB in both groups, with the more pronounced reduction in the normothermic patients. Haemoglobin and plasma viscosity were without differences between the groups. The lowest blood temperature in the hypothermic patients was 21.0 +/- 0.3 degrees C, and the lowest rectal temperature in these patients was 29.0 +/- 0.3 degrees C (20 minutes after start of CPB). Forehead- and forearm-LDF increased significantly in both groups by start of CPB. In the hypothermic patients, this increase was significantly lower, and LDFs were already reduced below baseline values five to 10 minutes after onset of CPB (LDF-forehead -18%, LDF-forearm -72%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

[Heart rhythm after conversion of ventricular tachyarrhythmia by internal shock delivery].

The purpose of this retrospective study is the analysis of dysrhythmias following internal cardioversion/defibrillation of ventricular tachycardia (VT) or fibrillation (VF) and to discuss their relevance to the therapy with automatic implantable devices. Therefore, 304 internal conversions of VT/VF during and/or after implantation of automatic defibrillators were evaluated in 51 patients. Significant post-shock arrhythmias (bradycardia, atrial fibrillation, non-sustained VT of > or = 10 cycles) were absent after 89% of internal shocks. Pauses of > 2 s were observed in 2/9 patients without VVI-back-up pacing. The heart rate was > or = 50 bpm in 10/51 patients. Atrial fibrillation occurred in 7 patients. Non-sustained, mostly polymorphic VT consisting of > or = 10 cycles followed 18/304 (6%) internal shocks in 13 patients. The VT rate was > or = 200/min in 17/18 episodes and triggered an inadequate shock once. The incidence of non-sustained VT post-shock was unrelated to shock energy, type, and duration of the converted arrhythmia. In conclusion, automatic implantable devices should provide back-up pacing. Tachycardic rhythms can mislead automatic interpretation of the effect of internal shocks.

Adult↗

PubMed1993

Circulatory effects of the PDE-inhibitors piroximone and enoximone.

1. The isolated circulatory response to intravenous application of the phosphodiesterase (PDE) inhibitors piroximone and enoximone was studied. 2. In a randomized sequence of 30 male patients undergoing elective aortocoronary bypass grafting either piroximone (0.5 mg kg(-1); n = 10) or enoximone (0.5 mg kg(-1); n = 10) were given during steady state of cardiopulmonary bypass (CPB). A group in which NaCl was given as a placebo served as a control (n = 10). 3. MAP was reduced by piroximone (maximum -23 mm Hg) and enoximone (maximum -18 mm Hg), whereas it increased in the control (+20 mm Hg). Volume of the extracorporeal circuit indicating venous pooling decreased more pronouncedly in the enoximone patients (-440 ml) than in the piroximone group (-300 ml). 4. Laser Doppler flows (LDFs) increased in both PDE-III inhibitor groups with the higher and longer increase in the enoximone-treated patients (LDF-forehead maximum +44%, LDF-forearm maximum +33%). Piroximone-induced increase in both LDFs was less pronounced with respect to both time and degree (LDF-forehead maximum +30%, LDF-forearm +12%). 5. Oxygen consumption (VO2) was significantly higher in the PDE-III inhibitor-treated than in the control patients. 6. Piroximone and enoximone showed significant vasodilatory properties at the arterial and venous side (= 'venous pooling'), from which patients with heart failure would profit. 7. Vasodilation could be observed for a longer period and was more pronounced in the enoximone-treated than in the piroximone patients. Alterations in capillary skin blood flow measured by laser Doppler technique gave evidence for an improvement in nutritive microcirculation, which was slightly more pronounced in the enoximone patients.

Aged↗

PubMed1992

[Constrictive pericarditis--surgery with or without heart-lung machine?].

In patients suffering from constrictive pericarditis, the best hemodynamic results can be achieved by total mobilization of the heart and complete resection of the pericardium. Among 72 patients operated upon from 1969 to 1991, the use of extracorporeal circulation became necessary only twice. Therefore, we suggest the use of heart lung machine only in patients with bad myocardial function or in patients who need correction of additional diseases. Routine use of extracorporeal circulation is not mandatory.

Diagnosis, Differential↗