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Biomedical subjects

I E Konstantinov

Publications and source records attributed to I E Konstantinov.

At least 19 recordsLinked to original sources
PubMed2006

Intermittent peripheral tissue ischemia during coronary ischemia reduces myocardial infarction through a KATP-dependent mechanism: first demonstration of remote ischemic perconditioning.

Remote ischemic preconditioning reduces myocardial infarction (MI) in animal models. We tested the hypothesis that the systemic protection thus induced is effective when ischemic preconditioning is administered during ischemia (PerC) and before reperfusion and examined the role of the K(+)-dependent ATP (K(ATP)) channel. Twenty 20-kg pigs were randomized (10 in each group) to 40 min of left anterior descending coronary artery occlusion with 120 min of reperfusion. PerC consisted of four 5-min cycles of lower limb ischemia by tourniquet during left anterior descending coronary artery occlusion. Left ventricular (LV) function was assessed by a conductance catheter and extent of infarction by tetrazolium staining. The extent of MI was significantly reduced by PerC (60.4 +/- 14.3 vs. 38.3 +/- 15.4%, P = 0.004) and associated with improved functional indexes. The increase in the time constant of diastolic relaxation was significantly attenuated by PerC compared with control in ischemia and reperfusion (P = 0.01 and 0.04, respectively). At 120 min of reperfusion, preload-recruitable stroke work declined 38 +/- 6% and 3 +/- 5% in control and PerC, respectively (P = 0.001). The force-frequency relation was significantly depressed at 120 min of reperfusion in both groups, but optimal heart rate was significantly lower in the control group (P = 0.04). There were fewer malignant arrhythmias with PerC during reperfusion (P = 0.02). These protective effects of PerC were abolished by glibenclamide. Intermittent limb ischemia during myocardial ischemia reduces MI, preserves global systolic and diastolic function, and protects against arrhythmia during the reperfusion phase through a K(ATP) channel-dependent mechanism. Understanding this process may have important therapeutic implications for a range of ischemia-reperfusion syndromes.

Adenosine Triphosphate↗
PubMed2006

Remote ischaemic preconditioning protects against cardiopulmonary bypass-induced tissue injury: a preclinical study.

OBJECTIVES: To test the hypothesis that remote ischaemic preconditioning (rIPC) reduces injury after cardiopulmonary bypass (CPB). DESIGN: Randomised study with an experimental model of CPB (3 h CPB with 2 h of cardioplegic arrest). Twelve 15 kg pigs were randomly assigned to control or rIPC before CPB and followed up for 6 h. INTERVENTION: rIPC was induced by four 5 min cycles of lower limb ischaemia before CPB. MAIN OUTCOME MEASURES: Troponin I, glial protein S-100B, lactate concentrations, load-independent indices (conductance catheter) of systolic and diastolic function, and pulmonary resistance and compliance were measured before and for 6 h after CPB. RESULTS: Troponin I increased after CPB in both groups but during reperfusion the rIPC group had lower concentrations than controls (mean area under the curve -57.3 (SEM 7.3) v 89.0 (11.6) ng.h/ml, p = 0.02). Lactate increased after CPB in both groups but during reperfusion the control group had significantly more prolonged hyperlactataemia (p = 0.04). S-100B did not differ between groups. Indices of ventricular function did not differ. There was a tendency to improved lung compliance (p = 0.07), and pulmonary resistance changed less in the rIPC than in the control group during reperfusion (p = 0.02). Subsequently, peak inspiratory pressure was lower (p = 0.001). CONCLUSION: rIPC significantly attenuated clinically relevant markers of myocardial and pulmonary injury after CPB. Transient limb ischaemia as an rIPC stimulus has potentially important clinical applications.

Animals↗
PubMed2002

Management of life-threatening haemoptysis.

Massive haemoptysis represents a major medical emergency that is associated with a high mortality. Here we present two cases of life-threatening haemoptysis, the first caused by rupture of an aortic aneurysm into the lung in a 37-yr-old woman with polyarteritis nodosa and the second caused by massive bleeding from an angiectatic vascular malformation in the right main bronchus in a 21-yr-old woman. Fibreoptic bronchoscopy played an essential role in the diagnostic process and management of the respiratory tract. Diagnosis in the first case was obtained by CT scan and the aneurysm was treated surgically. In the second case, bronchial arteriography contributed to both definitive diagnosis and treatment. Initial cardiorespiratory management, diagnostic procedures and definitive therapy are described and reviewed. Adequate early management of the cardiorespiratory system is essential to the outcome. Aggressive measures to elucidate the cause of haemoptysis and prompt therapy are warranted because of the high risk of recurrence.

Acute Disease↗
PubMed2001

Surgical treatment of persistent esophageal compression by an unusual form of right aortic arch.

A 32-year-old woman with dysphagia due to an unusual form of right aortic arch and anomalous left subclavian artery had successful repair after two previous failures. The definitive repair was accomplished by resection of the retroesophageal portion of the right aortic arch. The continuity of the aorta was established with a prosthetic graft. The operation was performed through a median sternotomy with cardiopulmonary bypass and circulatory arrest.

Adult↗
PubMed2001

Thrombosis of intracardiac or extracardiac conduits after modified Fontan operation in patients with azygous continuation of the inferior vena cava.

BACKGROUND: The Fontan procedure in patients with azygous continuation of the inferior vena cava, requires a cavo-pulmonary anastomosis, and deviation of the hepatic venous drainage to the pulmonary arteries using an intra- or extracardiac conduit. METHODS: We report thrombosis of two pericardial conduits and one Gore-Tex (W. L. Gore & Assoc, Flagstaff, AZ) graft used for deviation of hepatic venous blood to the pulmonary arterial tree in 3 patients aged 11, 24, and 28 years. Two of the conduits (pericardial) were intraatrial. The Gore-Tex graft was placed in an extracardiac position. The two pericardial conduits obstructed completely. RESULTS: One patient died at reoperation. In the 2nd patient, the conduit was excised and the hepatic veins were allowed to drain into the atrium. In the 3rd patient, partial thrombosis of the Gore-Tex conduit was noted 30 months after operation. The thrombus resolved with oral anticoagulation. CONCLUSIONS: Conduits carrying only hepatic venous blood flow may have a higher risk of thrombosis. Anticoagulation or alternative methods of directing hepatic blood flow to the pulmonary circulation must be considered in these patients.

Adult↗
PubMed2001

Wilhelm Ebstein and Ebstein's malformation.

In 1866, Wilhelm Ebstein published a scholarly description of a tricuspid valve anomaly with dilation of the right atrium and patent foramen ovale that bears his name. However, his original report was almost overlooked. Despite a wide range of publications on the history of cardiac pathology and cardiac surgery, the international literature provides only scarce information regarding the personality of Wilhelm Ebstein and his original description of the anomaly that bears his name. In this article, we present biographical data of Wilhelm Ebstein and discuss how his original description of autopsy findings correlates with our current knowledge of this congenital disorder. It is the excellent correlation of Ebstein's pathologic findings with clinical notes of his colleague and Ebstein's hypotheses of the pathophysiology that made his publication a landmark in the description of a new entity. In addition, Ebstein's report provided a strong basis for the development of repair techniques for this rare anomaly 100 years later.

Ebstein Anomaly↗
PubMed2001

Aortic root replacement in a patient with vancomycin-resistant Enterococcus faecium endocarditis and leukemia.

Vancomycin-resistant Enterococcus faecium endocarditis is rare and usually occurs in immunocompromised patients. We describe a patient with hairy-cell leukemia and vancomycin-resistant E faecium endocarditis. The patient presented with severe aortic insufficiency. He underwent aortic root replacement with a cryopreserved aortic homograft and was treated with a combination of quinupristin/dalfopristin, ampicillin, and gentamicin.

Acute Disease↗
PubMed2000

Sergei S. Brukhonenko: the development of the first heart-lung machine for total body perfusion.

Sergei S. Brukhonenko designed and constructed one of the earliest heart-lung machines. He was the first to experimentally perform a total body perfusion with the heart of the animal isolated from the circulation. His work paved the way to the first experimental operations on heart valves. Although Brukhoneko's pioneering contributions have not received the recognition they deserve, his work represents an important landmark in cardiac surgery.

Equipment Design↗
PubMed2000

Robert H. Goetz: the surgeon who performed the first successful clinical coronary artery bypass operation.

Robert H. Goetz performed the first successful clinical coronary artery bypass operation on May 2, 1960. He used a nonsuture technique to connect the right internal thoracic artery to the coronary artery by means of a modified Payr's cannula made of tantalum. The patency of the anastomosis was demonstrated angiographically and the patient remained free of angina pectoris for 1 year. It was an important and brave step forward, a step that was far ahead of its time. Unfortunately, his pioneering work was not appreciated and fell into oblivion.

Animals↗
PubMed2000

Yustin Y. Djanelidze and the first successful repair of an injured ascending aorta.

Yustin Y. Djanelidze is one of the little-known pioneers of cardiac surgery in the 20th century. He successfully sutured a penetrating injury of the ascending aorta in St. Petersburg, Russia, on 27 October 1913. To the best of our knowledge, this was the 1st case of ascending aorta repair described in the world medical literature.

Aorta↗
PubMed1999

Cavo-pulmonary shunt: from the first experiments to clinical practice.

The cavo-pulmonary anastomosis is often referred to as Glenn shunt today. The concept of cavo-pulmonary shunting, however, was developed independently by many surgeons. While the work of some of them is widely recognized, the pioneering contributions of many others fall into oblivion. Nonetheless, each of them contributed something original and precious to the total sum of our modern knowledge. It seems timely, as we enter the new millennium, to give due credit to those individuals who put their minds and efforts into helping sick children. These people deserve recognition.

Heart Bypass, Right↗
PubMed1999

The influence of sizing on the dynamic function of the free-hand implanted porcine aortic homograft: an in vitro study.

BACKGROUND AND AIMS OF THE STUDY: The influence of sizing on the function of a porcine aortic valve after its implantation using the free-hand technique in the subcoronary position was investigated. METHODS: Dynamic function and leaflet configuration of the valve (n = 16) were first analyzed in its natural aortic root in a left heart simulator at 120/80 mmHg pressure and 4 l/min cardiac output. The valve was then implanted in the recipient porcine aortic root and re-studied. Three groups were investigated: group I (n = 4) comprised of 1-2 mm smaller donor aortic valve than the recipient; group II (n = 8) 3-4 mm smaller; and group III (n = 4) 5-7 mm smaller. Orifice area (OA), systolic and diastolic configurations of the leaflets, pattern and timing of leaflet opening and closure, commissural movement, pressure gradient and valvular regurgitation were analyzed. RESULTS: In the intact donor aortic root, average expansion of the aorta at the commissures, for a pressure change from 0 to 80 mmHg, was about 42%. This was reduced significantly in all assemblies. Group I showed a 34% reduction in OA, and excessive leaflet bending; there was no aortic insufficiency (AI) or pressure gradient across the valve. In group III there was a lesser reduction in OA and reduced leaflet bending, but two of four valves had AI. In group II, the reduction in OA was only 13%, there was less leaflet bending, and no AI. CONCLUSIONS: The donor valve 3-4 mm smaller than the recipient seems an optimal match. The current practice of using the same size donor as recipient may be responsible for excessive leaflet bending and may be implicated in early deterioration of the homograft.

Animals↗
PubMed1998

A mystery of Vladimir P. Demikhov: the 50th anniversary of the first intrathoracic transplantation.

Vladimir P. Demikhov was the first to perform intrathoracic transplantation of the heart alone, lung alone, and the heart and lungs in a warm-blooded animal and the first to perform an experimental coronary artery bypass operation with success. He designed the first mechanical cardiac substitute and was one of the first to use the vascular stapling device in experiments. In 1960 Demikhov published the world's first monograph dealing with the subject of thoracic transplantation. This monograph, Experimental Transplantation of Vital Organs, became a "bible of intrathoracic transplantation" and deserves the recognition of everyone who is interested in organ transplantation. However, to say only that Demikhov was the first in the world who performed these operations is to say nothing. It is important to describe the circumstances under which these operations were done to appreciate the true scale of his innovations.

Animals↗