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Biomedical subjects

M Demkow

Publications and source records attributed to M Demkow.

At least 19 recordsLinked to original sources
PubMed2001

Transvenous closure of moderate and large secundum atrial septal defects in adults using the Amplatzer septal occluder.

The aim was to determine the feasibility of using the Amplatzer septal occluder for closure of moderate and large secundum atrial septal defects in adults. Fifty patients aged 16-76 years (mean +/- SD, 40 +/- 15.5), underwent successful device implantation. Flow ratios of 1.4-8.5 (mean +/- SD, 2.6 +/- 1.6) were calculated. The defects were: centrally placed (n = 31), antero-superior with partial or total deficiency of aortic rim (n = 19), multiple (n = 3) and with aneurysmal septum (n = 23). They measured 4-25 mm (median 14) on echocardiography and balloon sized 7-31 mm (median 19.5). Devices of 7-34 mm (median 20) were implanted. Patient follow up for 1 month (50/50 patients), 3 months (40/50) and 12 months (13/50), achieved respective rates of 90%, 92% and 98% of complete occlusion. In one patient a transient atrioventricular block (2:1) developed, and one had a transient STT elevation. One female had an episode of 30 min loss of vision over the lateral aspect of the left eye 3 months after implantation. In conclusion, transvenous occlusion of secundum atrial septal defects with the Amplatzer septal occluder in adults is safe, and can be performed without significant complications. Large defects, defects with a very deficient or absent aortic rim, defects with an aneurysmal septum as well as some multiple defects can be closed with an almost 100% early complete occlusion rate. This makes the procedure an alternative to surgery for selected adult patients.

Adolescent↗
PubMed2001

Transcatheter closure of a 16 mm hypertensive patent ductus arteriosus with the Amplatzer muscular VSD occluder.

There is little experience with transcatheter closure of very large, hypertensive patent ductus arteriosus. We present a case of successful closure of a 16 mm ductus with the Amplatzer VSD occluder, a device originally designed for transcatheter closure of congenital muscular ventricular septal defects. To our best knowledge this is the largest ductus ever closed by an interventional technique.

Adolescent↗
PubMed2000

Left ventricular outflow tract gradient decrease with non-surgical myocardial reduction improves exercise capacity in patients with hypertrophic obstructive cardiomyopathy.

OBJECTIVES: This study was undertaken to evaluate mid-term clinical results of non-surgical myocardial reduction in patients with hypertrophic obstructive cardiomyopathy. METHODS: Twenty-five patients with left ventricular outflow tract obstruction (mean gradient of 84. 54+/-31.38 mmHg) and symptoms of dyspnoea, angina and/or syncope were treated with non-surgical myocardial reduction. The patients were followed-up for a mean period of 10.44+/-1.8 months. In all patients clinical examination with echocardiography was repeated after every 3 months of follow-up, and a symptom-limited treadmill test was repeated at the 6 month follow-up. Eighteen patients underwent simultaneous respiratory gas analysis. RESULTS: Clinical follow-up examinations were achieved in all 25 patients. Persistent left ventricular outflow tract gradient reduction was seen in 23 patients. Seventeen patients had a reduction of left ventricular outflow tract gradient >50% of baseline value. Twenty patients showed a clinical improvement from 2.8+/-0.5 up to 1.2+/-0.5 NYHA class (P<0.001). The clinical improvement was matched by an improvement in objective measures of exercise capacity in patients with significant left ventricular outflow tract gradient reduction. Exercise time increased from 571.9+/-192.2 to 703.5+/-175.4 s, P<0. 001, and peak VO(2)increased from 14.6+/-5.2 to 20.5+/-8.6 ml. kg(-1)min(-1), P<0.05. CONCLUSION: Significant left ventricular outflow tract gradient reduction with exercise capacity improvement was achieved in the majority of patients treated with non-surgical myocardial reduction. We recommend this method as an alternative to surgery for symptomatic patients with hypertrophic obstructive cardiomyopathy.

Cardiac Catheterization↗
PubMed1999

Long-term follow-up results of balloon valvuloplasty for congenital aortic stenosis: predictors of late outcome.

AIMS: Long-term follow-up of patients with aortic valve stenosis undergoing balloon valvuloplasty was evaluated with respect to survival, the need for repeat intervention and factors predicting late outcome. METHODS AND RESULTS: Forty-five patients between 3.5 to 23 years old (mean 11.7 +/- 4.5) were followed for 62 +/- 30 months (range 11-122). The transvalvar aortic gradient decreased from 84 +/- 20 to 36 +/- 10 mmHg (p < 0.001) and remained significantly lower (50 +/- 26 mmHg; p < 0.001) at follow-up. At that time, 10 patients (including 4 with significant valve incompetence) had gradients >/= 60 mmHg. The procedure resulted in significant valve incompetence (grade >/= 3) in 8 patients (17.8%). There was a progression of incompetence and 13 patients (28.9%) had significant regurgitation at follow-up. All survived. Fifteen patients (33.3%) required re-intervention 51 +/- 24 months after valvuloplasty. The indications were: aortic stenosis in 5 patients; regurgitation in 6 patients; and stenosis with regurgitation in 4 patients. Actuarial freedom from re-intervention at 2, 4, 6 and 8 years was 96%, 88%, 61% and 56% of patients, respectively. The residual post-valvuloplasty gradient was the only predictor of re-intervention for valve stenosis (odds ratio = 3.2 for every 10 mmHg gradient increase; p = 0.017). A residual post-valvuloplasty gradient >/= 40 mmHg increased the relative risk of re-intervention sixfold. The immediate post-valvuloplasty aortic regurgitation grade was the only risk factor of re-intervention for regurgitation (odds ratio = 34 for every incompetence degree increase; p = 0.0019). Incompetence grade >/= 2 increased the risk of re-intervention tenfold. CONCLUSIONS: Valvuloplasty carries the risk of development of valve incompetence, which progresses with time. Some patients develop restenosis. The </= 10 year survival after the procedure is excellent, and 56% of patients are free of re-intervention at 8 years. The immediate post-valvuloplasty incompetence grade and transvalvar gradient are the predictors of late re-intervention.

Adolescent↗
PubMed1998

High-Pressure Bail-out Coronary Stenting Without Anticoagulation: Early Outcome and Follow-up Results.

PURPOSE:The purpose of this study is to assess the immediate outcome and long-term results of high pressure bail-out coronary stenting without subsequent anticoagulation. PATIENTS AND METHODS: Between June 1994 and September 1996, 32 consecutive patients (males 24, mean age 55 +/- 9.3 years) underwent bail-out stenting at a mean deployment pressure of 15.5 +/- 2.3 mmHg because of complicated PTCA. A total of 54 stents (Palmaz-Schatz, Micro, Gianturco Roubin and Wiktor) were implanted, from one to four stents into each vessel. After the procedure all patients were treated with ticlopidine 500 mg/day and acetylosalicylic acid 300 mg/day only. RESULTS: Stents were successfully delivered in all patients. In the cath lab procedural success was 96.9%. During the in-hospital phase, there was one (3.1%) acute stent thrombosis followed by urgent bypass surgery (CABG). Four (12.5%) non-Q wave myocardial infarctions occurred. There were no subacute stent thrombosis or hemorrhagic complications. Six month angiographic restudy in 28 patients showed restenosis in 13 (46.4%): 9 patients were treated successfully by rePTCA. At one year 13 (40.6%) major adverse cardiac events occurred: eleven (34.4%) target lesion revascularizations (9 PTCA, 2 CABG), one (3.1%) elective CABG surgery and one (3.1%) late cardiac death. Event-free survival was 93.8% at one month, 65.6% at six months, and 59.4% at one year. CONCLUSIONS: High pressure bail-out coronary stenting with antiplatelet regimen is an effective and safe procedure for treating complicated PTCA. Although the restenosis rate is high, in most cases in-stent restenosis can be treated by rePTCA. In 60% of patients clinical course at one year was uneventful.

Journal Article↗
PubMed1996

[Early and long-term outcome after coronary artery patency].

The role of percutaneous transluminal coronary angioplasty (PTCA) in the management of chronically occluded coronary arteries is still controversial. Percutaneous transluminal coronary angioplasty of chronic total occlusion is associated with relatively low success rates and a high incidence of restenosis. The purpose of this analysis was to determine, from the records of our institution, the efficacy and long-term outcome of angioplasty performed for chronic total occlusion defined as complete occlusion (Thrombolysis in Myocardial Infraction [TIMI] grade 0). PTCA was performed in 212 consecutive patients with chronically occluded coronary arteries and was successful in 125 (59%) patients. Complications were not observed. Successful initial PTCA was related to the clinical duration of occlusion and the type of guidewire (the primary success rate with the conventional guidewire was 49 (48%) versus 76 (69.1%) with Magnum Meier System p < 0.01). Repeat angiography was performed for 65 (52.0%) consecutive patients with successful initial PTCA and demonstrated restenosis in 34 (52.3%). 17 patients were successfully treated by a second PTCA. Restenosis or reocclusion was not clearly related to the residual stenosis post PTCA. In addition, the grade of collateral supply was not different in the vessels with and without restenosis.

Adult↗
PubMed1994

Reversal of ischaemic systolic and diastolic left ventricular dysfunction by successful coronary angioplasty in patients with non-Q wave anterior myocardial infarction.

The effect of PTCA on global and regional left ventricular systolic function, isovolumic relaxation, chamber and muscle stiffness were studied in 30 patients with angina pectoris, previous non-Q wave anterior myocardial infarction (AMI) and significant stenosis of the left anterior descending coronary artery (LAD). In 11 of the 30 patients the condition was stable, but it was unstable in 19. Left ventricular angiograms were obtained before and 4.85 +/- 3.67 months after PTCA. The RAO was in the 30 degree projection, with the silhouette of the left ventricle sliced into 90 regions; changes in left ventricular volume, pressure and anterior wall thickness during the full cardiac cycle, together with dp/dt were demonstrated. After PTCA, global ejection fraction increased from 68.77 +/- 5.96% to 76.57 +/- 3.18%, P < 0.001. Impaired contractility was found in 29/90 (32.2%) regions before PTCA and in 5/90 (5.6%) after PTCA, P < 0.001. The time constant of the isovolumic pressure fall decreased after PTCA (52.56 +/- 17.40 ms vs 39.61 +/- 11.26 ms, P < 0.01). Elastic chamber stiffness coefficient decreased (0.022 +/- 0.003 vs 0.008 +/- 0.004, P < 0.001) and peak rate of left ventricular filling increased (319.0 +/- 107.9 ml.min-1 vs 396.8 +/- 201.4 ml.min-1, P < 0.05) after PTCA. The muscle stiffness coefficient was within normal values before and did not change after PTCA. The study findings show that in patients with persistent angina pectoris after non-Q wave AMI, complex systolic and diastolic ischaemic dysfunction occurs. This dysfunction can be reversed after successful PTCA of LAD.

Adult↗
PubMed1994

Long term follow up after percutaneous mitral commissurotomy with the Inoue balloon-incidence of restenosis.

UNLABELLED: The long term outcome of 300 consecutive patients following percutaneous mitral commissurotomy (PMC) with the Inoue balloon was analyzed with regard to the incidence of restenosis. There were 256 females and 44 males (mean age 44.4 +/- 9.9 years, range 18-69 years), 52 had previous surgical commissurotomy, 96 were in atrial fibrillation, and 16 had a history of embolism. PCM was carried out with a success rate of 84% (no significant mitral regurgitation and mitral valve area (MVA) > 1.5 cm2). Two hundred and seventy patients were available for clinical and serial echocardiographic studies at six months, 12 months and once a year thereafter (18 patients operated on for mitral regurgitation less than six months after PMC, three patients lost to follow up, nine patients refused to return). MVA increased with PMC from 1.18 cm2 +/- 0.3 to 2.0 +/- 0.3 cm2 and then decreased to 1.8 +/- 0.3 at a mean follow up of 24.0 +/- 13.5 months (range 6-55). Echocardiographic restenosis (RS) (MVA at follow up < 1.5 cm2 with a 50% loss of the initial gain) was found in 38 patients (14%). Twenty-five (66%) of them remained in NYHA class I or II. Restenosis free survival according to the Kaplan-Mayer curve was 93%, 86%, 77% and 73% at 12,24,36 and 55 months respectively. None of the 24 clinical, hemodynamic, echocardiographic or procedural variables used on the Cox proportional hazard regression analysis identified predictors of restenosis free survival. CONCLUSIONS: The overall incidence of echocardiographic restenosis post PMC is low (12.6%) in patients followed for a mean period of two years and often occurs without worsened clinical symptoms. It may be difficult to define clinical, echocardiographic or procedural factors as significant predictors of restenosis free survival.

Adolescent↗
PubMed1992

[Complications of percutaneous transluminal coronary angioplasty (PTCA)].

Between 1981 and 1990, 714 patients underwent 756 percutaneous transluminal coronary angioplasty (PTCA) procedures. A total of 52 patients (6.9%) had major in-hospital complications: 5 patients (0.66%) died, Q-wave or non Q-wave myocardial infarction were observed in 13 patients (1.66%) during procedure and in 8 (1%) outside the catheterization laboratory, before discharge. Because of periprocedural occlusion 11 patients (1.5%) were managed with bypass surgery, 8 (1%) had a transient occlusion that was reopened with PTCA. 21 patients (2.8%) were not ++re-dilated but managed pharmacologically. Dissection, intracoronary thrombus and previous thrombolytic treatment were often associated with occlusion. The risk of dissection was related to lesion morphology. Long-(more than 1 cm) lesion, eccentric stenosis and tortuosity of the vessel segment undergoing dilatation were risk factors for occlusive dissection. There was a high risk of side branch occlusion if its take-off was narrowed and side branch originated from the target lesion. One of the most important risk predictors is the amount of jeopardized myocardium supplied by the target coronary artery. Acute closure of an artery supplying large amount of myocardium may cause abrupt hemodynamic collapse. Hypotension secondary to the artery occlusion may cause a decrease of the flow in the other coronary arteries, leading to cardiogenic shock. Although it is important to note that patients with unstable angina, intracoronary thrombus, long and complex lesion, severe multivessel disease and compromised left ventricular function are at higher risk of acute complication, PTCA is a relatively safe procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1992

[Percutaneous pulmonary valvuloplasty in 135 patients].

We present our 7 years experience with 135 pts aged 1.4-44 years (mean 10-yrs) in whom percutaneous balloon valvuloplasty (BPV) for congenital pulmonary stenosis was attempted. In 4 pts we failed to place the balloon at valvar level, in another four BPV was repeated so, 135 procedures in 131 pts were performed. Balloon diameter/pulmonary anulus diameter ratio (BD/PD) ranged from 0.9 to 1.85 (mean 1.37). In 10 cases double balloon technique was used. Immediate results: in the whole group of 131 pts the right ventricular-pulmonary artery gradient (RV-PAG) was reduced from 74 +/- 42 to 34 +/- 34 mm Hg, and right ventricular systolic pressure (RVSP) decreased from 92 +/- 41 to 54 +/- 34 mm Hg just after BPV. 86 pts (65.6%)--group I, had good immediate result of BPV (RVSP less than 50 mm Hg). 4 of them had dysplastic pulmonary valves (DPVs). RV-PAG in 82 pts with normal valves decreased from 53 +/- 25 to 15 +/- 7 mm Hg right after BPV. In 45 pts (34.4%)--group II, immediate result of valvuloplasty was recognised as unsatisfactory (RVSP greater than or equal to 50 mm Hg): in 4 of them BD/PD was smaller or equal 1.2 (subgroup IIa); 34 others had significant subpulmonary obstruction (SPO) that appeared or increased after BPV (subgroup IIb); and in remaining 7, DPVs were noticed (subgroup II c).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Percutaneous transluminal coronary angioplasty in patients with high risk bypass surgery].

The purpose of this study was to assess the immediate and long-term results of incomplete percutaneous transluminal coronary angioplasty (PTCA) in high-risk coronary artery bypass surgery (CABG) patients. 24 pts (male-22, female-2, age - 39-60 years) were divided into 2 groups: I-8 pts with unstable angina pectoris who were definitely not CABG candidates because of very low ejection fraction (LVEF < 24%) and/or diffuse coronary atherosclerosis; II-16 pts selected for CABG only after failed PTCA. From this group 12 pts with unstable angina pectoris and history of myocardial infarction were at higher CABG risk because of LVEF < 40% and diffuse coronary atherosclerosis. 4 pts were poor surgical candidates because of coexistent medical disorders. The strategy of PTCA was to dilate first the most critical (culprit) lesion, responsible for the patient symptoms, usually situated in the artery supplying large area of viable myocardium. We did not achieve: complete revascularization in all our pts (incomplete revascularization by intent). Initial success rate of the PTCA in both groups was 100%. There were no serious complications. During follow-up (6 months--4 yrs) long-term clinical improvement was observed in 7 pts from group I (87.5%) and 14 pts from group II (87.5%). We conclude, that in most pts with unstable angina pectoris and with high-risk of CABG good immediate and long-term results of incomplete PTCA can be achieved.

Adult↗
PubMed1990

Temperature-dependence of the effect of trifluoperazine as a protective agent during cardioplegia in the isolated working rat heart.

The duration of ischemia resulting in 50% post-ischemic recovery of hemodynamic functions was 25 min in the control isolated working rat hearts and increased to 45 min in the hearts subjected to normothermic cardioplegia plus normothermic global ischemia (36 degrees C) and to 180 min in the hearts subjected to hypothermic cardioplegia and hypothermic ischemia (22 degrees C). Addition of 10(-6) M trifluoperazine to the normothermic St. Thomas' cardioplegic solution considerably improved the protective properties of the solution as assessed by the functional recovery of the heart. Under conditions of hypothermic ischemic arrest the drug failed to improve the protective properties of cardioplegic solution, suggesting a common modality between hypothermia and trifluoperazine-induced protection.

Animals↗
PubMed1990

[Complex angioplasty (PTCA) in the treatment of coronary artery stenosis].

56 patients with more than one stenotic coronary artery were treated by complex PTCA with success rate of 96.4%. Complications occurred in 3.6% of pts. Restenoses were found in 9.4% of pts; only one of the dilated arteries were restenosed. 11.3% of pts had repeated PTCA, because of progression of stenosis in other than previously treated artery. Angina occurred earlier in pts with restenoses than in pts with progression of stenoses. Late efficacy (mean 19 months) of complex PTCA was high (90.7%).

Adult↗
PubMed1989

[Angioplasty in acute and chronic occlusion of the coronary arteries].

An attempt of mechanical restoration of coronary artery patency and its angioplasty was carried out in 37 patients including 9 with acute myocardial infarction within 5 hours after the onset of an angina pain. The procedure was effective in 17 patients (45.9%), including 6 with acute myocardial infarction (66.7%). Mean time of a coronary artery occlusion was 5.1 weeks in the group with a good result in comparison with 17.2 weeks in the group with the unsuccessful procedure. In patients in whom restoration of a coronary artery patency was carried out within up to 3 months after its occlusion the procedure was effective in 64 per cent of them. Effectiveness of restoration of a coronary artery patency and its dilatation depends on the time from its occlusion to the procedure. The early attempt of the restoration of a coronary artery patency is effective in the majority of patients. In cases of the unsuccessful recanalization of a coronary artery occluded for a short time the main limitation of the procedure effectiveness was the vessel anatomy. The follow-up of 17 patients after a successful procedure showed restenosis or reocclussion in 6 of them (35%). It was referred in 1 case to the patient in whom restoration of a vessel patency was carried out during acute myocardial infarction (17%), and in 5 others to patients with a chronic occlusion of a coronary artery (45.5%).

Acute Disease↗