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Biomedical subjects

G Kirkorian

Publications and source records attributed to G Kirkorian.

At least 37 records · Page 2Linked to original sources
PubMed1998

Troponin I, troponin T, or creatine kinase-MB to detect perioperative myocardial damage after coronary artery bypass surgery.

STUDY OBJECTIVES: To compare cardiac troponin I (cTnI), cardiac troponin T (cTnT), and creatine kinase MB (CKMB mass) in patients with and without new Q wave on the ECG following coronary artery bypass graft (CABG) surgery. PATIENTS: After ethic committee's approval and informed consent, 82 patients, mean age 63+/-10 years, scheduled for CABG were included. INTERVENTIONS: Arterial blood samples were drawn during cardiopulmonary bypass, before, and 6, 12, 24, and 48 h after aortic cross-clamp release. cTnI, cTnT, and CKMB mass were measured. The appearance of new Q wave on the ECG performed preoperatively and 24 h postoperatively was used to assess myocardial lesion independently of biological markers. RESULTS: There were 69 patients without new Q wave on the ECG (group 1) and 13 with (group 2). In group 1, cTnI reached a peak of 2.1 microg/L (median, interquartile range [IQ]=2.4) at 12 h, cTnT increased progressively with a peak of 0.22 microg/L (IQ=0.2) at 48 h, and CKMB presented an earlier peak of 10 microg/L (IQ=6.2) at 6 h. Starting with the same median value, group 2 patients presented significantly higher peaks: cTnI: 17 microg/L (IQ=16) at 12 h; cTnT: 1.4 microg/L (IQ=2.3) at 12 h; and CKMB mass: 74 microg/L (IQ=61) at 6 h. Receiver operating characteristic (ROC) curves were constructed. The area under the curve was 0.90 for cTnI, 0.84 for CKMB, and 0.81 for cTnT (not significant). The best cutoff values to discriminate between group 1 and group 2 patients were determined with the ROC curves: cTnI=5 microg/L; CKMB mass=20 microg/L; cTnT=0.3 microg/L. Sensitivity, specificity, and positive and negative values for cTnI (5 microg/L) were 91%, 82%, 53%, and 98%, respectively. CONCLUSIONS: There was little differences among cTnI, cTnT, and CKMB after CABG to diagnose myocardial damage as assessed by new Q wave on the ECG. There was a trend of cTnI to be a better discriminator than cTnT, but it did not reach statistical significance.

Biomarkers↗
PubMed1998

[Infections secondary to implantation of cardiac pacemakers].

Infectious complications of pacemaker implantation are not common but may be particularly severe. Localised wound infections at the site of implantation have been reported in 0.5% of cases in the most recent series with an average of about 2%. The incidence of septicaemia and infectious endocarditis is lower, about 0.5% of cases. The operator's experience, the duration of the procedure and repeat procedures are considered to be predisposing factors. The main cause of these infections is though to be local contamination during the implantation. The commonest causal organism is the staphylococcus (75 to 92%), the staphylococcus aureus being the cause of acute infections whereas the staphylococcus epidermis is associated with cases of secondary infection. The usual clinical presentation is infection at the site of the pacemaker but other forms such as abscess, endocarditis, rejection of the implanted material, septic emboli and septic phlebitis have been described. The diagnosis is confirmed by local and systemic biological investigations and by echocardiography (especially transoesophageal echocardiography) in cases of right heart endocarditis. There are two axes of treatment: bactericidal double antibiotherapy and surgical ablation of the infected material either percutaneously or by cardiotomy. Though controversial, and unsupported by scientific evidence, the role of systematic, preoperative, prophylactic antibiotic therapy in the prevention of these complications seems to be increasing.

Abscess↗
PubMed1997

Mechanical cardiac valve thrombosis in patients in critical hemodynamic compromise.

BACKGROUND: Valve obstruction is a life threatening complication of mechanical valve prosthesis. METHODS: From 1985 to 1993, 29 consecutive patients were hospitalized in our intensive care unit for mechanical prosthetic valve thrombosis (PVT). There were 12 men and 17 women aged 25-75 years (57 +/- 12). Prosthetic valve location was mitral in 14 patients, aortic in 6, aortic and mitral in 9. PVT occurred from 15 days to 174 months (67 +/- 52 months) after surgery. Delay from first symptoms to hospitalization ranged from 1 to 45 days (11 +/- 11). RESULTS: First clinical symptoms were progressive left heart failure in 17 patients, stroke in 6, and chest pain in 6. Furthermore, acute myocardial infarction was later documented in 3. Left heart failure NYHA III-IV was present in 26 patients (90%) on admission and 10 of those were in cardiogenic shock. Anticoagulation regimen was inadequate in 13 cases (45%). It has been recently stopped in 8 patients and incorrectly conducted in 5. Total hospital mortality was 41.3% (12). It was independent of type and position of the valve prosthesis. Diagnosis of PVT was only made at autopsy in 3 patients who died of recurrent myocardial infarction (2) or cardiogenic shock (1). Five further patients died before any surgery could be attempted (cardiac arrest: 2, cardiogenic shock: 3). Valve replacement could be done in 21 cases, 7 of whom were in cardiogenic shock and 9 had severe pulmonary edema. Four patients died after surgery, the operative mortality was 19%. CONCLUSION: PVT remains a serious complication of mechanical heart valve prostheses. Overall mortality rate is high, related to difficulty to diagnosis, delay to hospitalization and severe clinical condition at admission. In our study, operative risk remained acceptable even when the clinical presentation was severe.

Adult↗
PubMed1997

Risk stratification after myocardial infarction. A reappraisal in the era of thrombolysis. The Groupe d'Etude du Pronostic de l'Infarctus du Myocarde (GREPI)

OBJECTIVES: The present study was performed to evaluate whether the modalities of risk stratification after myocardial infarction were still operative in the thrombolytic era. BACKGROUND: Prediction of fatal events in the aftermath of myocardial infarction relies on tests which aim to assess myocardial function, residual ischaemia and propensity for ventricular arrhythmias. Recent data on improved myocardial infarction prognosis have led to the view that risk stratification needs to be updated. METHODS: In this multicentre, prospective study, 471 acute myocardial infarction patients, 45% of whom were given thrombolytic therapy, were enrolled from the 10th day and underwent all or part of the following tests exercise test, radionuclide ventriculography (resting and exertional ejection fraction). Holter monitoring, signal-averaged electrocardiography and programmed electrical stimulation. Univariate and multivariate analyses were performed to identify predictors of mortality. RESULTS: One year and long-term (mean follow-up 31.4 months) mortality rates were 5.5% and 8.4%, respectively. Prediction of mortality was assessed and the role of the following variables was thus determined: age over 56 years (P = 0.01), previous coronary attacks (P < 0.001), history of heart failure (P < 0.001), early heart failure after myocardial infarction (P = 0.017), maximum workload of lest than 120 W at exercise test (P = 0.014), ineligibility to perform exercise (P = 0.002), depressed left ventricular ejection fraction (P = 0.013), late potentials as identified using 50 Hz high pass filtering (P = 0.012), mean night-time cycle length of less than 750 ms (P < 0.001), standard deviation of day time RR intervals of less than 100 ms (P = 0.04), the last two measures reflecting heart rate variability. In this population, neither ventricular ectopic activity nor inducibility of sustained monomorphic ventricular tachycardia at electrophysiological study carried any prognostic significance. Multivariate analyses showed that decreased heart rate variability, presence of late potentials and low ejection fraction (< 30%) made an independent contribution to the survival models. CONCLUSION: In the current context of management of acute coronary patients, the basis for risk stratification after myocardial infarction remain roughly unchanged.

Adult↗
PubMed1997

Cardiac troponin I does not increase after cardioversion.

BACKGROUND: Serum total creatine kinase (total CK) level increases in the patients following electrical cardioversion. The same has been observed with CK-MB, an isoenzyme of the total CK with some cardiospecificity. Cardiac troponin I (cTnI), a new specific cardiac biological marker, is highly effective to discriminate myocardial and muscular injuries after noncardiac surgery. METHODS: To assess cardiac damage after cardioversion, we measured serum cTnI, myoglobin, total CK, CK-MB mass, 1, 2, 3, 4, 8, 12, and 24 h after elective cardioversion of supraventricular tachycardia in 28 patients (eight women, 20 men; mean age, 64 +/- 10 years). Cumulative energy was below 370 J in 17 patients, between 370 and 900 J in eight patients, and 1,020 J in three patients. Serum cTnI was measured using a sandwich immunoenzymologic assay. The detection limit of the assay was 0.35 microgram/L and normal values range from 0.35 to 1.3 micrograms/L. RESULTS: In all but three patients, cTnI remained below 0.35 microgram/L. In these three patients, cTnI ranged between 0.35 and 0.9 microgram/L. There was no correlation between cTnI and the number or the energy of cardioversion. Myoglobin and total CK increased to abnormal concentrations in 11 patients (myoglobin, 630 +/- 190 micrograms/L, and total CK, 2,584 +/- 780 U/L) and reached myocardial infarction-like values in five patients. Modest increases of CK-MB were then also observed. A strong correlation was observed between the total energy of direct current cardioversion and the increase of either myoglobin (r = 0.87; p < 001) or total CK (r = 0.81; p < 001). CONCLUSION: Cardioversion in a clinical setting does not induce elevation of cTnI. Increase in total CK, CK-MB, and myoglobin may be due solely to muscular lesions and is closely related to the cumulative energy delivered.

Aged↗
PubMed1997

Defibrillation threshold and electrode configurations: an experimental study testing three configurations in twelve pigs.

OBJECTIVE: The choice between epicardial or subcutaneous patches remains unclear and depends essentially on the team's habits. This study tested how much an additional patch can decrease defibrillation threshold (DFT), and compared a Subcutaneous Array and an epicardial patch. Today most implantable automatic defibrillators have a transvenous endocardial configuration alone but when the DFT remains high an additional patch is necessary. EXPERIMENTAL DESIGN: Three different configurations were tested with biphasic shocks in 12 pigs: Endovenous lead (Endo), Endovenous lead + subcutaneous patch (Endo + SQ) and Endovenous lead + epicardial patch (Endo + Epi). For each animal DFTs were determined in a balanced random order for the 3 configurations. Ventricular fibrillation was induced by pacing (30 Hz, 8 V, for 5 seconds). DFT was accurately measured with the up/down procedure until 3 reversal of defibrillation success or failure occurred. DFTs (mean +/- SD) were extracted and compared using paired t test and analysis of variance. RESULTS: DFTs were 14.6 +/- 11.0 J for Endo and significantly decreased (p < 0.01) when an additional SQ (9.4 +/- 7.2 J) or epicardial patch (8.9 +/- 6.5 J) was added to endovenous lead, without significant difference between Endo + SC and Endo + Epi configurations. CONCLUSIONS: Regarding this important decrease of DFT (respectively -35% for Endo + SC and -39% for Endo + Epi), additional patches should be more often recommended in patients with low safety margin of DFT. In those cases subcutaneous patches should be preferred instead of epicardial patches. Moreover, an additional reason to recommend this attitude could be the possible generator batteries saving.

Animals↗
PubMed1997

Retrospective risk analysis for early heart-related death after cardiomyoplasty. The Worldwide Cardiomyoplasty Group.

BACKGROUND: Dynamic cardiomyoplasty is an evolving treatment for heart failure that uses an electrically stimulated latissimus dorsi muscle wrapped around the heart to improve cardiac function. Preoperative patient characteristics and deaths after cardiomyoplasty have been recorded during the past 5 years in a cumulative database representing worldwide experience of 42 medical centers. METHODS: Statistical models of hazards (monthly death rates) were used to identify risk factors for transiently increased risk of cardiovascular mortality within 2 months after cardiomyoplasty. RESULTS: Actuarial survival (n = 261) was 88%, 80%, and 76% at 1, 3, and 6 months after cardiomyoplasty, respectively. The peak hazard of 6% dying per month occurred during the first month after the surgical procedure. Lower ejection fraction, increased number of major coronary arteries with > or = 70% stenotic lesions, and lower chronotropic responses during exercise were independent risk factors for the transient increase in early cardiovascular mortality. Early risk of cardiovascular mortality was significantly reduced as centers gained experience with more than 3 patients. CONCLUSION: Early survival after cardiomyoplasty has improved with experience and might be reduced further by preoperative assessments that identify patients at highest risk.

Actuarial Analysis↗
PubMed1997

[Acute dissection of the thoracic aorta. Symptoms and complications].

Acute dissection of the aorta is an increasingly recognised pathology, the diagnosis of which is sometimes delayed despite the fact that advances in medical imaging provide almost perfect diagnostic accuracy. Some of the symptoms are particularly suggestive. Chest pain is the key symptom, and the greater the intensity, usually described as a migratory intrathoracic tearing sensation irradiating towards the lumbar region. The other symptoms become meaningful in association with this pain: paraplegia, acute peripheral ischaemia, hemiplegia. Clinical examination is capital when a diastolic murmur of aortic regurgitation is heard or when a distal pulse is absent, the blood pressure is asymmetric or a pericardial rub is detected. The frighteningly poor initial prognosis of acute dissection of the aorta has been transformed by surgery, providing, that it is performed early. Optimal therapeutic results can only be obtained by and early diagnosis.

Acute Disease↗
PubMed1996

[Brucella pancarditis with fatal outcome].

Brucella endocarditis was diagnosed in a 21-year-old itinerant farm worker hospitalized for acute pulmonary edema. History taking revealed cough, fever and sweating one month earlier which had been treated with antibiotics. At admission, echography showed lesions on the aortic valve and hemocultures identified Brucella meltensis. On day 7 of specific treatment with doxycycline (200 mg/day) and rifamycine (1200 mg/day), and despite digitalics and diuretics, left ventricular failure rapidly worsened, leading to cardiac arrest and death before emergency surgery could be performed. Autopsy showed occlusive vegetations on the aortic valves facing the right coronary ostium, deep ulceration of the valsava sinus with abscess formation and fibrino-hemorragic pericarditis involving both the anterior and posterior walls of the epicardium. Gram negative germs were evidenced in the abscess alone. This case emphasizes the potentially rapid destructive effect of Brucella melitensis and confirms that surgery is the safest therapeutic alternative for aortic valve localizations. Surgery should be performed without delay.

Adult↗
PubMed1996

Stratification of time-frequency abnormalities in the signal-averaged high-resolution ECG in postinfarction patients with and without ventricular tachycardia and congenital long QT syndrome.

Having developed sound mathematical techniques that allow precise mapping of cardiac signals in the time-frequency (TF) and time-scale planes, the next important issue is to extract from these representations information that best reflects the electrophysiologic and anatomic derangement unique to patients at risk of arrhythmias and other cardiac diseases. In this study, the authors present a new method that stratifies the magnitude of the TF transforms of abnormal cardiac signals into distinguishing features by comparing the means of the coefficients of the TF transforms of any study population to the corresponding means of a control population using a standard ANOVA technique. This results in a three-dimensional mapping of the high-resolution ECG into time, frequency, and P value components. Significant energy increases are given positive P values and depressed energies are given negative P values: these are ranked according to a color scale. The method was tested on two study populations: postmyocardial infarction patients with documented ventricular tachycardia (MI+VT, n = 23) and without (MI-VT, n = 40) and patients with congenital long QT syndrome (LQTS, n = 19). Two groups of healthy control subjects (n = 31 and n = 40) were used as a reference group matched for sex. The study results were based on the Morlet analyzing wavelets, with frequencies ranging from 40 to 250 Hz in 10 logarithmically progressing scales, and computed millisecond per millisecond over a 350-ms analyzing time window, starting from 100 ms before the onset of the QRS. The patients with MI+VT displayed significantly increased high-frequency components in the 40-250-Hz frequency range, corresponding to prolonged QRS duration and late potentials in the area from 80 to 150 ms after QRS onset. Significantly depressed energy (P < 10(-4)) was also observed for the 40-106-Hz frequency range in the first 50 ms of the QRS complex, mainly in lead Y and in the magnitude vector. In patients with LQTS, significant modifications (P < 10(-2)) were observed in the first half of the QRS and in the ST-segment, in all leads, revealing anomalies in the genesis of the ventricular depolarization and repolarization processes. In conclusion, the authors propose a new method for the stratification of abnormal TF components occurring in the signal-averaged high-resolution electrocardiogram of patients at risk of VT and fibrillation under different pathologic conditions.

Adult↗
PubMed1996

Symptomatic pericardial disease associated with patch electrodes of the automatic implantable cardioverter defibrillator: an underestimated complication?

Constrictive pericarditis can be associated with ICD patch electrodes. During a mean follow-up of 24 months, in a population of 35 patients who received ICDs with a patch electrodes configuration, we identified three patients with clinical and hemodynamic signs compatible with this event. Patient 1, a 35-year-old male, underwent implantation of an ICD because of a primary electrical disease complicated by cardiac arrest. Fourteen months later he complained of exertional dyspnea without any signs of heart failure. Right heart catheterization showed high filling pressures and diastolic dip and plateau in pressure curves. Thoracotomy and pericardial exploration were performed. Three months after removal of the patches and insertion of an endocardial lead system, the patient had normal respiration. Patients 2 and 3, who suffered from coronary heart disease without heart failure, exhibited a hemodynamic profile suggestive of constrictive pericarditis: in one patient, 10 months after ICD implantation, associated with right heart failure; and in the other, 18 months after ICD implantation with left heart failure. Patch electrodes were removed in these two patients and replaced by endocardial lead electrodes with subsequent clinical improvement. It is concluded that constrictive pericarditis related to epicardial patch is not an uncommon occurrence during ICD therapy and should be considered in patients who show clinical signs of cardiac decompensation.

Adult↗
PubMed1996

Thoracoscopic approach to implantable cardioverter defibrillator patch electrode implantation.

Even if transvenous lead system for automatic implantable cardioverter defibrillators (ICDs) has been one of the main surgical advances in the recent past, its major limitation is the high defibrillation thresholds in some cases. Thus, an additional patch may be required and implanted either in a subcutaneous position or in an epicardial position. We describe another possibility: the implantation of extrapericardial patch under video-thoracoscopic control. This new technique allows a deep implantation of the whole material without thoracotomy. Seven patients were included in our preliminary experience. During defibrillation threshold evaluation, two patients required 34 J with the single transvenous lead system, and five patients were not defibrillated with the single lead system; therefore, they required a 300-J external rescue shock. We decided to implant an additional patch in those seven patients with high defibrillation thresholds. This patch was inserted into the pleural cavity through a left subcostal incision. Under video thoracoscopy, it was positioned and stitched onto the pericardium. The defibrillation generator was then implanted through the left subcostal incision in a subdiaphragmatic space. As a result, preoperative defibrillation thresholds were significantly reduced (14.29 +/- 3.45 J, mean +/- SD) and remained stable during follow-up controls (eighth day and second month). Long-term follow-up (14 +/- 4.5 months) was uneventful, with an excellent tolerance for the patients. In conclusion, extrapericardial implantation of defibrillation patches under video thoracoscopy is an easy technique that allows low defibrillation thresholds.

Adult↗
PubMed1996

Improved appraisal of the quality of life in patients with automatic implantable cardioverter defibrillator: a psychometric study.

BACKGROUND: Patients with an implanted cardioverter defibrillator (ICD) may experience a certain degree of suffering. A sample of 32 patients was surveyed to determine the psychological benefit resulting from this treatment. METHODS: Hamilton Anxiety Scale, Beck Depression Inventory and a shortened version of the Minnesota Multiphasic Personality Inventory were used. A 10-item scale and a global index of quality of life were especially designed to assess cardioverter defibrillator tolerance and the effect of its implantation on patients' current well-being. RESULTS: Both quality of life index scores were negatively correlated with anxiety and depression. Occurrence of shocks had no influence on psychological well-being. CONCLUSIONS: The questionnaires provided a simple and reliable measure of quality of life in ICD patients. Prior to implantation, technical explanations should be accompanied by stress management techniques adapted to the patients' psychological background.

Adaptation, Psychological↗
PubMed1996

[Aneurysms of the left ventricle without atheromatous coronary artery disease. Apropos of 2 cases].

Left ventricular aneurysms are usually secondary to myocardial infarction with atheromatous coronary artery disease. The authors report two rare cases of non-atheromatous left ventricular apical aneurysms. The first case was clearly post-traumatic but the diagnosis in the second case was more difficult. The authors discuss the aetiological diagnosis of these rare non-atheromatous aneurysms in adults and the therapeutic management with respect to these two cases and a review of the literature.

Coronary Angiography↗
PubMed1996

[Predictive factors of induction of ventricular arrhythmia under amiodarone].

A good result of electrophysiological investigations under amiodarone therapy distinguishes a low risk group of patients with malignant ventricular arrhythmias. The authors set out to determine the factors predictive of this response in order to identify patients better protected by amiodarone at an earlier stage. Fourty-five patients with an average age of 56 years, were referred for evaluation of severe ventricular arrhythmias, monomorphic ventricular tachycardia being inducible during electrophysiological investigation in all cases before treatment. Amiodarone was prescribed orally at degressive doses. A control electrophysiological study was performed 4 to 6 weeks later. Eighteen patients (40%) were considered to be responders (absence of inducible ventricular arrhythmia or inducible non-sustained tachycardia or tachycardia with a cycle length increased by over 100 ms with respect to the base-line study). The other 27 patients were considered to be non-responders. No clinical or paraclinical parameter was found to distinguish responders from non-responders. The authors conclude that the data obtained before control electrophysiological investigation under amiodarone does not allow prediction of the response to this drug. The search for early prognosis of the efficacy of amiodarone in preventing ventricular arrhythmias therefore requires electrophysiological investigation after impregnation.

Adult↗
PubMed1996

[Thrombosis on the mitral valve prosthesis and disseminated cancer: treatment by fibrinolysis].

The authors report the case of a 63-year-old woman with occlusive thrombosis of a mitral valve prosthesis and cardiogenic shock successfully treated by systemic thrombolytic therapy. This treatment was given despite metastatic hepatic and bone breast cancer. This, and other recently reported cases, argues in favour of widening the indication of thrombolysis as treatment of first intention in cases of obstruction of atrioventricular valve prostheses. Nevertheless, the relative safety of surgical treatment and the risk of systemic thromboembolism of thrombolysis, incites caution and reservation of medical therapy for carefully selected patients.

Breast Neoplasms↗