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1.
Nervenarzt ; 90(1): 71-72, 2019 01.
Article in German | MEDLINE | ID: mdl-30302515

ABSTRACT

BACKGROUND: Electroconvulsive therapy (ECT) is a highly effective, yet still controversial therapy for both the general public and psychiatrists. In this study, we investigated the patients' view regarding effectiveness and tolerability of electroconvulsive therapy under consideration of individual clinical response. MATERIAL AND METHODS: In 31 patients with major depression, subjective effectiveness and tolerability were assessed via a differentiated questionnaire prior to, during, and after ECT. Symptoms were rated using the Montgomery-Åsberg depression rating scale (MADRS) and the Beck depression inventory II (BDI­II) RESULTS: Patients assessed ECT to be generally effective both before and after the treatment. This view was independent of their individual treatment success. In contrast, patients' rating of individual effectiveness depended on the objective improvement of their symptoms. Side effects were rated to be generally slight to moderate. CONCLUSION: Against the background of persisting criticism towards ECT, the viewpoint of involved patients provides us with important references for an appropriate judgement of this therapy. The results suggest a good benefit-risk ratio for ECT from the patients' perspective.

2.
Nervenarzt ; 89(11): 1271-1276, 2018 11.
Article in German | MEDLINE | ID: mdl-30171302

ABSTRACT

Background: Electroconvulsive therapy (ECT) is a highly effective, yet still controversial therapy for both the general public and psychiatrists. In this study, we investigated the patients' view regarding effectiveness and tolerability of electroconvulsive therapy under consideration of individual clinical response. Material and Methods: In 31 patients with major depression, subjective effectiveness and tolerability were assessed via a differentiated questionnaire prior to, during, and after ECT. Symptoms were rated using the Montgomery-Åsberg depression rating scale (MADRS) and the Beck depression inventory II (BDI-II). Results: Patients assessed ECT to be generally effective both before and after the treatment. This view was independent of their individual treatment success. In contrast, patients' rating of individual effectiveness depended on the objective improvement of their symptoms. Side effects were rated to be generally slight to moderate. Conclusion: Against the background of persisting criticism towards ECT, the viewpoint of involved patients provides us with important references for an appropriate judgement of this therapy. The results suggest a good benefit-risk ratio for ECT from the patients' perspective.


Subject(s)
Depressive Disorder, Major , Electroconvulsive Therapy , Depressive Disorder, Major/therapy , Electroconvulsive Therapy/standards , Humans , Patient Satisfaction , Psychiatric Status Rating Scales , Surveys and Questionnaires , Treatment Outcome
3.
Am J Physiol Endocrinol Metab ; 306(6): E697-706, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24452455

ABSTRACT

The question whether K⁺ depolarization is an appropriate experimental substitute for the physiological nutrient-induced depolarization of the ß-cell plasma membrane was investigated using primary mouse ß-cells and islets. At basal glucose 40 mM K⁺ induced a massive monophasic response, whereas 15 mM K⁺ had only a minimal insulinotropic effect, even though the increase in the cytosolic Ca²âº concentration ([Ca²âº]i) was not inferior to that by 20 mM glucose. In voltage-clamp experiments, Ca²âº influx appeared as nifedipine-inhibitable inward action currents in the presence of sulfonylurea plus TEA to block compensatory outward K⁺ currents. Under these conditions, 15 mM K⁺ induced prolonged action currents and 40 mM K⁺ transformed the action current pattern into a continuous inward current. Correspondingly, 15 mM K⁺ led to an oscillatory increase and 40 mM K⁺ to a plateau of [Ca²âº]i superimposed on the [Ca²âº]i elevated by sulfonylurea plus TEA. Raising K⁺ to 15 or 40 mM in the presence of sulfonylurea (±TEA) led to a fast further increase of insulin secretion. This was reduced to basal levels by nifedipine or CoCl2. The effects of 15 mM K⁺ on depolarization, action currents, and insulin secretion were mimicked by adding 35 mM Cs⁺ and those of 40 mM K⁺ by adding 35 mM Rb⁺, in parallel with their ability to substitute for K⁺ as permeant cation. In conclusion, the alkali metals K⁺, Rb⁺, or Cs⁺ concentration-dependently transform the pattern of Ca²âº influx into the ß-cell and may thus generate stimuli of supraphysiological strength for insulin secretion.


Subject(s)
Calcium Signaling , Cell Membrane/metabolism , Insulin-Secreting Cells/metabolism , Insulin/metabolism , Membrane Potentials , Potassium/metabolism , Animals , Calcium Channel Blockers/pharmacology , Calcium Signaling/drug effects , Cell Membrane/drug effects , Cells, Cultured , Cesium/metabolism , Glucose/metabolism , Hypoglycemic Agents/pharmacology , Insulin Secretion , Insulin-Secreting Cells/cytology , Insulin-Secreting Cells/drug effects , Islets of Langerhans/drug effects , Islets of Langerhans/metabolism , Membrane Potentials/drug effects , Mice , Mice, Inbred Strains , Osmolar Concentration , Patch-Clamp Techniques , Potassium Channel Blockers/pharmacology , Rubidium/metabolism , Tissue Culture Techniques
4.
Folia Morphol (Warsz) ; 73(4): 514-20, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25448914

ABSTRACT

Coronary artery fistulae (CAF) are anomalies related to coronary artery abnormal termination. This is a very rare congenital malformation accounting for about 0.2-0.4% of congenital cardiac anomalies, but in some patients it can be haemodynamically important. Single-photon emission computed tomography or positron emission tomography myocardial perfusion imaging (MPI) using radioactive agents is widely used in clinical practice for cardiac ischaemia detection as a very sensitive and non-invasive tool. We are going to present 2 patients with bilateral CAFs to the pulmonary trunk without signs of the rest or stress ischaemia in MPI.

5.
Encephale ; 39(2): 137-42, 2013 Apr.
Article in French | MEDLINE | ID: mdl-23107463

ABSTRACT

INTRODUCTION: Chronic depression is a frequent disorder and is usually treated using traditional approaches. These approaches rarely take into account the psychopathological specificities of the chronic evolution of the disorder. OBJECTIVE: The present article aims at presenting the specific psychopathological nature of chronic depression and puts forward a treatment model that is particularly adapted to these specificities. TREATMENT MODEL: The treatment model, Cognitive Behavioral Analysis System of Psychotherapy (CBASP; according to McCullough) is based on two theoretical models: the developmental theory by J. Piaget and the interpersonal model by D. Kiesler. According to McCullough, the cognitive affective functioning of chronically depressed patients is comparable with the one of a child who has not reached the Piagetian stage of logical operations. Their thinking is global, pre-logical and presents with monologues, instead of internal dialogues. These patients are incapable of effective controlling and regulating of emotions and of constructive accommodation of established schemas, when confronted with novel experiences. Finally, these patients are unaware of their interpersonal effects on the environment they unwillingly have. The latter are conceptualized using Kiesler's conceptualization of psychopathology. According to this model, the patient sends implicit relational "messages" provoking interpersonal "pulls" in the interaction partner (e.g., the therapist). These pulls are assessed and may be graphically represented using a Circumplex Model, also called the Kiesler-circle, and is the basis of the case conceptualization in the psychotherapy with chronically depressed patients. CBASP has developed based on the clinical implications of these models and combines them in an original fashion. PRESENTATION OF MAIN THERAPEUTIC INTERVENTIONS: Two lines of intervention result from the models: (1) situational analysis, which analyzes the links between behavior in a particular situation and the person's goal or desire related to the particular situation, and (2) interpersonal techniques based on the notions of transference and counter-transference. On one hand, situational analysis follows several steps linking the patient's behavior with his/her desired outcome, which is compared to the real outcome in the situation. The patient's interpretations are amended in a second step, using the desired outcome as an anchor. On the other hand, interpersonal techniques imply the therapist's stance of disciplined personal involvement, meaning a controlled way of therapist self-disclosure facing the patient, with the aim of experiencing by the patient, that his/her behavior does not remain without specific, immediate and authentic consequences in the environment. This experience by the patient should allow him/her to (re-)establish the perceived functionality of the patient's behavior in interpersonal encounters. DISCUSSION AND CONCLUSIONS: We underline the relevance of the approach by citing several empirical studies which have established the efficacy of the model, in specific clinical conditions that are the combined treatment with anti-depressant medication, a sufficient number of sessions and in the case of early trauma as etiological factor of the chronic depression. We discuss the application of CBASP to other clinical diagnoses, such as borderline and avoidant personality disorder as well as disorders related to substance abuse and thus argue in favor of CBASP as a central model in the treatment of various mental illnesses.


Subject(s)
Cognitive Behavioral Therapy/methods , Depressive Disorder/therapy , Chronic Disease , Countertransference , Depressive Disorder/diagnosis , Depressive Disorder/psychology , Depressive Disorder, Major/diagnosis , Depressive Disorder, Major/psychology , Depressive Disorder, Major/therapy , Dysthymic Disorder/diagnosis , Dysthymic Disorder/parasitology , Dysthymic Disorder/therapy , Emotional Intelligence , Generalization, Psychological , Humans , Interpersonal Relations , Logic , Psychopathology , Social Behavior , Social Environment , Thinking , Transference, Psychology
6.
Diabetologia ; 55(11): 3071-82, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22898767

ABSTRACT

AIMS/HYPOTHESIS: Inspired by recent speculation about the potential utility of α(2A)-antagonism in the treatment of type 2 diabetes, the study examined the contribution of α(2)-antagonism vs other mechanisms to the antihyperglycaemic activity of the imidazoline (±)-efaroxan. METHODS: Effects of the racemate and its pure enantiomers on isolated pancreatic islets and beta cells in vitro, as well as on hyperglycaemia in vivo, were investigated in a comparative manner in mice. RESULTS: In isolated perifused islets, the two enantiomers of efaroxan were equally potent in counteracting inhibition of insulin release by the ATP-dependent K(+) (K(ATP)) channel-opener diazoxide but (+)-efaroxan, the presumptive carrier of α(2)-antagonistic activity, was by far superior in counteracting inhibition of insulin release by the α(2)-agonist UK14,304. In vivo, (+)-efaroxan improved oral glucose tolerance at 100-fold lower doses than (-)-efaroxan and, in parallel with observations made in vitro, was more effective in counteracting UK14,304-induced than diazoxide-induced hyperglycaemia. The antihyperglycaemic activity of much higher doses of (-)-efaroxan was associated with an opposing pattern (i.e. with stronger counteraction of diazoxide-induced than UK14,304-induced hyperglycaemia), which implicates a different mechanism of action. CONCLUSIONS/INTERPRETATION: The antihyperglycaemic potency of (±)-efaroxan in mice is almost entirely due to α(2)-antagonism, but high doses can also lower blood glucose via another mechanism. Our findings call for reappraisal of the possible clinical utility of α(2A)-antagonistic compounds in recently identified subpopulations of patients in which a congenitally higher level of α(2A)-adrenergic activation contributes to the development and pathophysiology of type 2 diabetes.


Subject(s)
Adrenergic alpha-Antagonists/pharmacology , Benzofurans/pharmacology , Diabetes Mellitus, Type 2/drug therapy , Hyperglycemia/drug therapy , Imidazoles/pharmacology , Insulin-Secreting Cells/drug effects , Adrenergic alpha-2 Receptor Antagonists/pharmacology , Animals , Antihypertensive Agents/pharmacology , Brimonidine Tartrate , Calcium/metabolism , Cells, Cultured , Diabetes Mellitus, Type 2/metabolism , Diazoxide/pharmacology , Female , Hyperglycemia/metabolism , Insulin/metabolism , Insulin-Secreting Cells/cytology , Insulin-Secreting Cells/metabolism , KATP Channels/physiology , Male , Membrane Potentials/drug effects , Membrane Potentials/physiology , Mice , Mice, Inbred C57BL , Patch-Clamp Techniques , Quinoxalines/pharmacology , Yohimbine/pharmacology
7.
Am J Physiol Endocrinol Metab ; 303(2): E223-33, 2012 Jul 15.
Article in English | MEDLINE | ID: mdl-22550068

ABSTRACT

Depolarization by a high K(+) concentration is a widely used experimental tool to stimulate insulin secretion. The effects occurring after the initial rise in secretion were investigated here. After the initial peak a fast decline occurred, which was followed by a slowly progressive decrease in secretion when a strong K(+) depolarization was used. At 40 mM KCl, but not at lower concentrations, the decrease continued when the glucose concentration was raised from 5 to 10 mM, suggesting an inhibitory effect of the K(+) depolarization. When tolbutamide was added instead of the glucose concentration being raised, a complete inhibition down to prestimulatory values was observed. Equimolar reduction of the NaCl concentration to preserve isoosmolarity enabled an increase in secretion in response to glucose. Unexpectedly, the same was true when the Na(+)-reduced media were made hyperosmolar by choline chloride or mannitol. The insulinotropic effect of tolbutamide was not rescued by the compensatory reduction of NaCl, suggesting a requirement for activated energy metabolism. These inhibitory effects could not be explained by a lack of depolarizing strength or by a diminished free cytosolic Ca(2+) concentration ([Ca(2+)](i)). Rather, the complexation of extracellular Ca(2+) concomitant with the K(+) depolarization markedly diminished [Ca(2+)](i) and attenuated the inhibitory action of 40 mM KCl. This suggests that a strong but not a moderate depolarization by K(+) induces a [Ca(2+)](i)-dependent, slowly progressive desensitization of the secretory machinery. In contrast, the decline immediately following the initial peak of secretion may result from the inactivation of voltage-dependent Ca(2+) channels.


Subject(s)
Calcium/metabolism , Insulin/metabolism , Islets of Langerhans/metabolism , Potassium/pharmacology , Animals , Choline/pharmacology , Hypoglycemic Agents/pharmacology , Insulin Secretion , Islets of Langerhans/drug effects , Lipotropic Agents/pharmacology , Mannitol/pharmacology , Membrane Potentials/drug effects , Membrane Potentials/physiology , Mice , Sodium Chloride/pharmacology , Tolbutamide/pharmacology
8.
Am J Cardiol ; 80(7): 878-82, 1997 Oct 01.
Article in English | MEDLINE | ID: mdl-9382001

ABSTRACT

The effects of various physiologic and pharmacologic stimuli on the anterograde slow pathway in patients with atrioventricular nodal reentrant tachycardia are well characterized. We sought to further characterize the nature of anterograde and retrograde conduction during tachycardia and to define the differential input of the parasympathetic nervous system to these pathways. A custom-made neck suction collar was placed to stimulate the carotid body baroreceptors during supraventricular tachycardia. Neck suction at -60 mm Hg was applied and changes in tachycardia cycle length, AH, and ventriculoatrial intervals were measured in 20 patients. These measurements were repeated after intravenous administration of 10 mg of edrophonium to enhance vagal tone. We observed a 15 +/- 6 ms increase in tachycardia cycle length from baseline (p <0.0001) and a 14 +/- 6 ms increase in AH interval (p <0.0001), but no change in the VA interval with neck suction alone. The tachycardia cycle length prolonged 26 +/- 55 ms (p <0.0001) with edrophonium and an additional 12 +/- 43 ms (p <0.001) with neck suction after edrophonium. There was no change in the VA interval before or after edrophonium during neck suction. There were 10 tachycardia terminations in 8 patients during anterograde slow pathway block during neck suction, with tachycardia cycle length prolongation and mean AH prolongation before termination of 45 +/- 37 ms (vs 15 +/- 7 ms increase in AH interval without tachycardia termination, p = 0.10). There were 12 tachycardia terminations in 4 patients with retrograde block during neck suction, only after edrophonium, without any preceding change in tachycardia cycle length during 11 episodes. We conclude that anterograde slow pathway demonstrates gradual conduction slowing with parasympathetic enhancement, whereas retrograde fast pathway responds with abrupt block.


Subject(s)
Atrioventricular Node/physiopathology , Parasympathetic Nervous System/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Atrioventricular Node/anatomy & histology , Edrophonium/pharmacology , Female , Humans , Male , Middle Aged , Parasympathetic Nervous System/drug effects , Pressure
9.
Am J Cardiol ; 78(11): 1289-92, 1996 Dec 01.
Article in English | MEDLINE | ID: mdl-8960594

ABSTRACT

We studied the effects of edrophonium on sinus cycle length, atrioventricular (AV) nodal fast pathway refractoriness, and AV nodal Wenckebach cycle length in 21 patients with AV nodal reentrant tachycardia (AVNRT) who received edrophonium, and 8 patients who received phenylephrine before and after selective slow pathway ablation. Changes in sinus cycle length, fast pathway conduction, and refractoriness were not altered by radiofrequency ablation of the slow pathway, suggesting that parasympathetic denervation does not occur after slow pathway ablation of AVNRT.


Subject(s)
Atrioventricular Node/innervation , Catheter Ablation/adverse effects , Sinoatrial Node/innervation , Tachycardia, Atrioventricular Nodal Reentry/physiopathology , Tachycardia, Atrioventricular Nodal Reentry/surgery , Vagus Nerve/physiopathology , Adult , Aged , Aged, 80 and over , Atrioventricular Node/drug effects , Edrophonium/pharmacology , Female , Humans , Male , Middle Aged , Neural Conduction/drug effects , Neural Conduction/physiology , Parasympathomimetics/pharmacology , Phenylephrine/pharmacology , Postoperative Period , Sinoatrial Node/drug effects , Sympathomimetics/pharmacology , Vagus Nerve Injuries
10.
Am J Kidney Dis ; 38(4): 770-6, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11576880

ABSTRACT

Ruptured intracranial aneurysm (RICA) is a life-threatening complication of autosomal dominant polycystic kidney disease (ADPKD). A family history of RICA may be a risk factor for RICA. Six hundred eight adult members of 199 ADPKD families were interviewed, and family pedigrees were constructed. Individuals were classified as having definite, probable, or possible RICAs from evidence and history obtained in interviews. Central nervous system (CNS) events not consistent with RICA were classified as other CNS events. Seventy-seven CNS events occurred in 906 subjects with ADPKD (8.5%) versus 13 events in 823 subjects without ADPKD (1.6%; P < 0.0001). No event in subjects without ADPKD was consistent with an RICA. Twenty-seven other (non-RICA) CNS events occurred in subjects with ADPKD (3%) versus 13 events in subjects without ADPKD (1.6%; P = 0.05). The frequency of RICA was increased in subjects with ADPKD: 21 definite RICAs in subjects with ADPKD (2%) versus none in subjects without ADPKD (P < 0.001); 28 definite and probable RICAs in subjects with ADPKD (3%) versus none in subjects without ADPKD (P < 0.001); and 50 definite, probable, and possible RICAs in subjects with ADPKD (5.5%) versus none in subjects without ADPKD (P < 0.001). The null hypothesis that RICAs are randomly distributed among subjects with ADPKD was tested for definite RICAs (n = 21), definite and probable RICAs (n = 28), and definite, probable, and possible RICAs (n = 50). In the three categories, the null hypothesis was rejected at P less than 0.05, P less than 0.05, and P less than 0.005, respectively. Vascular CNS events occurred more frequently in ADPKD than non-ADPKD family members, and clustering of RICAs occurred in families with ADPKD.


Subject(s)
Aneurysm, Ruptured/genetics , Intracranial Aneurysm/genetics , Polycystic Kidney Diseases/genetics , Adult , Family , Female , Humans , Male , Monte Carlo Method , Pedigree
11.
Ann Thorac Surg ; 57(4): 1018-9, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8166500

ABSTRACT

Accidental hypothermia associated with near-drowning and cardiac arrest has a high mortality, especially in the adult. We report the resuscitation of a 31-year-old man who suffered extended ice-water submersion, severe hypothermia (23 degrees C), and prolonged (> or = 78 minutes) cardiac asystole. A modified portable cardiopulmonary bypass system and femoral-femoral cannulation in the Emergency Department permitted the rapid institution of core rewarming, oxygenation, and controlled reperfusion, with a successful outcome. Rapid initiation of cardiopulmonary bypass outside the operating room can be an initial treatment option in this unique clinical situation.


Subject(s)
Cardiopulmonary Bypass/methods , Heart Arrest/therapy , Hypothermia/therapy , Immersion/adverse effects , Off-Road Motor Vehicles , Adult , Cardiopulmonary Bypass/instrumentation , Emergency Service, Hospital , Heart Arrest/etiology , Humans , Hypothermia/etiology , Male , Time Factors , Treatment Outcome
12.
Cathet Cardiovasc Diagn ; 25(2): 161-3, 1992 Feb.
Article in English | MEDLINE | ID: mdl-1531942

ABSTRACT

The syndrome of coronary-subclavian steal presenting with angina pectoris after coronary revascularization with the mammary arteries is not common. This disorder should be suspected in post LIMA patients with blood pressure differences between the arms and confirmed by angiography. PTA of the subclavian artery via the brachial approach, in appropriately selected patients, offers potential advantages over carotid subclavian bypass including an apparent lower complication rate with equally good results. Recurrences, which are apt to be more common after PTA versus carotid subclavian bypass, are easily managed with repeat dilatation. This course of management in our patient resulted in an excellent clinical outcome without complication. This report emphasizes the importance of considering subclavian stenosis in patients with prior LIMA bypass grafting, particularly when the ipsilateral arm blood pressure is reduced. In such cases, subclavian PTA offers a reasonable nonsurgical approach for correction.


Subject(s)
Angioplasty, Balloon , Coronary Disease/surgery , Graft Occlusion, Vascular/therapy , Internal Mammary-Coronary Artery Anastomosis , Postoperative Complications/therapy , Saphenous Vein/transplantation , Subclavian Steal Syndrome/therapy , Aged , Angioplasty, Balloon, Coronary , Coronary Angiography , Humans , Male
13.
Acta Physiol Scand ; 159(3): 189-98, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9079149

ABSTRACT

The effects of bradykinin, histamine and serotonin on vascular resistance and microvascular permeability were investigated in isolated cell-free perfused rabbit lungs. The capillary filtration coefficient was determined from the slope of lung weight changes over periods of venous pressure elevation before application of bradykinin (n = 6), histamine (n = 6) and serotonin (n = 6), and 5, 20 and 50 min afterwards. To prevent rapid inactivation of bradykinin by the angiotensin-converting enzyme in the pulmonary circulation, the bradykinin effects were additionally studied in the presence of the angiotensin-converting enzyme inhibitor captopril (n = 6). Bolus application of each substance resulted in a short-lasting increase in the pulmonary vascular resistance (3.7-9.1 mmHg). Which was most pronounced in the bradykinin+captopril group. The capillary filtration coefficient was significantly increased after histamine application, and to an even greater extent after serotonin application, whereas bradykinin on its own, as well as bradykinin given in the presence of captopril, had no measurable influence on capillary filtration in the lung. As a result of the bradykinin challenge, there was an immediate massive generation of prostacyclin, which could not be further augmented by a application. Histamine injection entailed a delayed onset of prostacyclin generation after the second stimulation, whereas no prostacyclin increase was measured in the serotonin-treated lungs. Thromboxane A2 generation was exclusively observed after the first serotonin application. The data exemplify different pathophysiological characteristics of bradykinin, histamine and serotonin on lung barrier function. Histamine and serotonin induce oedema formation by enhancing microvascular permeability, whereas bradykinin does not.


Subject(s)
Bradykinin/pharmacology , Histamine/pharmacology , Pulmonary Circulation/drug effects , Serotonin/pharmacology , 6-Ketoprostaglandin F1 alpha/metabolism , Animals , Capillaries/drug effects , Cell Membrane Permeability/physiology , Microcirculation/drug effects , Organ Culture Techniques , Rabbits , Thromboxane A2/biosynthesis , Thromboxane A2/metabolism
14.
Appl Opt ; 37(21): 4991-7, 1998 Jul 20.
Article in English | MEDLINE | ID: mdl-18285968

ABSTRACT

A fiber optic system for water analysis with high transparency in the deep-UV region (lambda >/= 190 nm) is presented. The system consists of special UV-improved silica fibers and a liquid-core waveguide (LCW) as an optical cell. The apertures of both light guides, the silica fiber and the LCW, are matched. The optical losses of the device are investigated experimentally and compared with theory, especially with a standard free-space geometry. The performance of the system with respect to UV absorption spectroscopy is demonstrated for nitrate and chlorine pollution in pure water. For a 203-mm-long LCW the detection limits have been determined to be as low as 22 mug/L for nitrate and 26 mug/L for chlorine.

15.
Pacing Clin Electrophysiol ; 15(11 Pt 1): 1661-6, 1992 Nov.
Article in English | MEDLINE | ID: mdl-1279532

ABSTRACT

The differentiation between ventricular tachycardia (VT) and sinus tachycardia (ST) is problematic in some patients with implantable defibrillators and/or antitachycardia pacemakers. The integral of the ventricular endocardial evoked response, or paced depolarization integral (PDI), has been demonstrated to undergo characteristic changes with a variety of stimuli including catecholamines, pacing rate, and exercise. We hypothesized that the PDI recorded from a unipolar transvenous right ventricular endocardial catheter would differentiate VT from ST. The PDI was calculated from a unipolar pacing stimulus, delivered via a cathode in the right ventricular apex, and the reference electrode, a quadripolar catheter positioned in the superior vena cava. PDIs were measured in 22 patients during VT and sinus rhythm. The PDI measured during sinus rhythm was 579 +/- 240 microV-sec and the PDI during VT was 894 +/- 411 microV-sec (P < 0.001). In a subset of seven patients, PDIs were measured during VT, sinus rhythm, and ST induced by catecholamine infusion or exercise. In this subset, the PDI during sinus rhythm was 645 +/- 295 microV-sec, during ST 588 +/- 308 microV-sec (9% decrease from sinus, P = 0.05), and during VT 863 +/- 342 microV-sec (33.9% increase, P = 0.01). These data indicate that the measurement of the PDI is potentially useful in differentiating VT from ST.


Subject(s)
Cardiac Pacing, Artificial/methods , Tachycardia, Sinus/diagnosis , Tachycardia, Ventricular/diagnosis , Ventricular Function, Right/physiology , Algorithms , Cardiac Catheterization , Diagnosis, Differential , Evoked Potentials/physiology , Female , Humans , Male , Tachycardia, Sinus/physiopathology , Tachycardia, Ventricular/physiopathology
16.
Pacing Clin Electrophysiol ; 16(9): 1842-52, 1993 Sep.
Article in English | MEDLINE | ID: mdl-7692417

ABSTRACT

In order to examine the effects of ventricular distention on the unipolar electrogram (UEG), an isolated rabbit heart modified Langendorff preparation was utilized. Left ventricular (LV) volume was adjusted using ionically permeable (PB = 9 hearts) or ionically impermeable balloons (IB = 4 hearts). LV UEGs, LV end-diastolic pressure (EDP), and LV minor axis dimension (MAD), as measured by ultrasonic transducers, were recorded. Three hundred twenty-five electrograms were digitized and analyzed with custom-designed software. In the PB group, a significant inverse linear relationship was found between UEG amplitude and changes in MAD (P < 0.0001). For each animal, this relationship had an R value > 0.8 and a P value < 0.0001. There was also a significant inverse linear relationship between UEG slope and changes in MAD (P < 0.01). UEG amplitude and slope also exhibited a significant inverse relationship to changes in LV EDP, which were best described by a third order polynomial function. In the IB group, no significant relationship was found between either UEG amplitude or slope and MAD or EDP. In this study, intracavitary volume exerted a profound and significant influence on UEG amplitude and slope. This effect was due to increases in conductive intraventricular volume and not to myocardial stretch.


Subject(s)
Electrocardiography , Stroke Volume , Ventricular Function, Left , Animals , Female , In Vitro Techniques , Male , Rabbits , Ventricular Pressure
17.
J Card Surg ; 8(2): 156-60, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8461498

ABSTRACT

While the development of pharmacological cardioplegic solutions for myocardial protection during cardiopulmonary bypass (CPB) have significantly lengthened the safe operating time for cardiac surgical procedures, the introduction of hypothermic hyperkalemic cardioplegia (CPG) has markedly increased the incidence of postoperative arrhythmias and conduction abnormalities. Using a customized modification of a computerized mapping system, we have developed a large animal porcine model of CPB that is exquisitely sensitive to the electrophysiological (EP) derangements imposed by ischemia and cardiac arrest. This model is able to measure spatial and temporal parameters of ventricular activation with high resolution, using an array of up to 84 epicardial electrodes that can be reproducibly placed on the surface of the heart utilizing known epicardial anatomical markers (e.g., coronary arteries). With this system we have measured the spectrum of clinically observed EP disturbances caused by CPG, from slowed intraventricular conduction to complete heart block. Compared to the control group of hypothermia alone, 2 hours of crystalloid CPG arrest had a significant slowing effect on ventricular activation (p < 0.05). CPG was accompanied, in each animal, by profound changes in the spatial distribution of ventricular activation and persistent slowing of ventricular activation. Traditional EP parameters of effective refractory period and pacing threshold were unchanged by CPG. Smaller temporal and spatial changes were observed in the control group, but were always reversed by 90 minutes of warm reperfusion. We conclude that CPG induces injury of the specialized conducting system and, to a lesser degree, the myocardium. This model will afford us the opportunity to test new methods of CPG to further improve myocardial preservation during CPB.


Subject(s)
Cardiopulmonary Bypass , Heart Arrest, Induced/methods , Heart/physiopathology , Animals , Body Temperature , Disease Models, Animal , Electrophysiology , Heart Conduction System/physiopathology , Myocardium/pathology , Swine , Ventricular Function/physiology
18.
Pacing Clin Electrophysiol ; 17(12 Pt 1): 2285-91, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7885936

ABSTRACT

While several reports have documented the safety of implantation of transvenous pacemakers in patients with epicardial patch-based implantable cardioverter defibrillators (ICDs), the implantation of transvenous pacemakers in patients with transvenous (nonthoracotomy) ICDs has not been well-described. We present three patients with transvenous ICDs who subsequently underwent implantation of transvenous pacemakers without complication. Technical considerations and a testing, protocol for detection of pacemaker-ICD interactions are discussed.


Subject(s)
Defibrillators, Implantable , Pacemaker, Artificial , Aged , Arrhythmias, Cardiac/physiopathology , Arrhythmias, Cardiac/therapy , Electrocardiography , Humans , Male , Pacemaker, Artificial/adverse effects , Thoracotomy
19.
Pacing Clin Electrophysiol ; 16(11): 2202-9, 1993 Nov.
Article in English | MEDLINE | ID: mdl-7505935

ABSTRACT

Sinus node reentrant tachycardia is a relatively uncommon (5%-15%) form of recurrent paroxysmal supraventricular tachycardia (SVT). We describe a case of symptomatic sinus node reentrant tachycardia in a 67-year-old male with ischemic heart disease, congestive heart failure, and depressed ventricular function. Adenosine administered during an electrophysiology study caused prolongation of the tachycardia cycle length due to atrial cycle length prolongation (without atrio-His prolongation) prior to tachycardia termination. Right atrial mapping revealed the earliest site of atrial activation in the high lateral right atrium just below the superior vena cava. Low energy (10 and 20 W) radiofrequency lesions were applied at this site with termination of the tachycardia within 3 seconds of radiofrequency energy delivery. Tachycardia could not be reinduced after delivery of the radiofrequency lesions. The sinus node function immediately and 6 weeks after radiofrequency catheter ablation remained normal and the patient was without clinical recurrence of SVT. Mapping of sinus node reentrant tachycardia and elimination of the reentrant circuit with radiofrequency catheter ablation is possible without causing sinus node dysfunction. Adenosine causes prolongation of the atrial cycle length followed by termination of sinus node reentrant tachycardia.


Subject(s)
Catheter Ablation , Tachycardia, Sinoatrial Nodal Reentry/surgery , Adenosine/administration & dosage , Aged , Cardiac Pacing, Artificial , Electrocardiography , Humans , Male , Tachycardia, Sinoatrial Nodal Reentry/physiopathology
20.
Pacing Clin Electrophysiol ; 18(2): 367-9, 1995 Feb.
Article in English | MEDLINE | ID: mdl-7731886

ABSTRACT

We report a patient with incessant atrial tachycardia and AV nodal reentrant tachycardia tachycardia and AV nodal reentrant tachycardia beginning almost 18 months following a successful maze procedure. Both tachycardias were cured by radiofrequency ablation. We speculate that the right atrial tachycardia may have been related to the maze procedure. Finally, we believe this report should emphasize the importance of careful and long-term follow-up of all patients undergoing the maze procedure. Proper evaluation of the place of this therapy greatly depends on reporting of all short- and long-term complications of this new procedure.


Subject(s)
Atrial Fibrillation/surgery , Postoperative Complications/etiology , Tachycardia, Atrioventricular Nodal Reentry/etiology , Tachycardia, Supraventricular/etiology , Aged , Catheter Ablation , Electrocardiography , Follow-Up Studies , Heart Atria/surgery , Humans , Male , Postoperative Complications/surgery , Tachycardia, Atrioventricular Nodal Reentry/surgery , Tachycardia, Supraventricular/surgery , Time Factors
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