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1.
Dtsch Med Wochenschr ; 125(37): 1065-8, 2000 Sep 15.
Article in German | MEDLINE | ID: mdl-11036483

ABSTRACT

BACKGROUND AND OBJECTIVE: Compared with conventional echocardiography (CEC) harmonic imaging (HEC) provides better resolution of the endocardial line and valvular apparatus. This prospective study was undertaken to compare the value of harmonic and conventional transthoracic echocardiography in endocarditis and compare them with standard transoesophageal echocardiography (TOE) and operative findings. PATIENTS AND METHOD: Conventional and harmonic echocardiographic imaging was compared in 30 patients (aged 58 +/- 17 years; 19 males and 11 females) with endocarditis clinically judged to require surgical intervention. The results of both methods were then compared with those of standard TOE and the intraoperative findings. RESULTS: Intraoperatively 15 floating structures, 9 abscesses and 5 perforations were demonstrated. Transoesophageal echocardiography was better than the standard method in diagnosing floating structures and detecting abscesses (15 vs. 10 vegetations, p < 0.05; 7 vs. 5 abscesses, p = 0.05). TOE was better than either method in the diagnosis of abscess. CONCLUSION: Harmonic transthoracic echocardiography is better than the conventional mode in diagnosing complications of endocarditis.


Subject(s)
Echocardiography/methods , Endocarditis/diagnosis , Abscess/diagnosis , Adult , Aged , Aortic Valve , Endocarditis/surgery , Female , Heart Valve Diseases/diagnosis , Humans , Image Enhancement , Male , Middle Aged , Mitral Valve , Prospective Studies , Rupture, Spontaneous/diagnosis
2.
Dtsch Med Wochenschr ; 125(37): T1-T4, 2000.
Article in German | MEDLINE | ID: mdl-12751012

ABSTRACT

Penetrating atherosclerotic ulcer of the thoracic aorta descendens. HISTORY AND CLINICAL FINDINGS: A 75-year-old man with a history of generalised atherosclerosis was admitted to hospital for invasive assessment of progredient typical angina pectoris. Apart from diminished peripheral pulses, physical examination was normal. INVESTIGATIONS: Coronary angiography revealed a three vessel coronary artery disease. The chest X-ray showed elongation and dilatation of the distal aortic arch and the proximal descending aorta thoracalis. Computed tomography and magnetic resonance imaging of the thorax as well as magnetic resonance angiography of the thoracic aorta, demonstrated a penetrating atherosclerotic ulcer of the descending aorta thoracalis, with extensive intramural hematoma. TREATMENT AND COURSE: After percutaneous ballon-dilatation of the right coronary artery and the circumflex artery, the patient was asymptomatic. Considering all aspects of the patients condition, medical treatment of the penetrating atherosclerotic ulcer was decided for the patient. The findings of the thoracic computed tomography after 6 months were unchanged. CONCLUSION: The penetrating atherosclerotic ulcer of the thoracic aorta is a less known clinical entity. Our case report demonstrates that even extensive forms can be clinical asymptomatic and discovered by routine radiologic examinations.

3.
Am J Cardiol ; 84(9): 1023-8, 1999 Nov 01.
Article in English | MEDLINE | ID: mdl-10569657

ABSTRACT

This study assesses the incidence of right atrial (RA) chamber and appendage thrombosis in patients with atrial fibrillation (AF) in relation to RA appendage morphology and function. Transthoracic and multiplane transesophageal echocardiography were performed in 102 patients with AF to assess the incidence of RA and left atrial (LA) thrombi and spontaneous echo contrast. Both right and left ventricular sizes, atrial chamber and appendage sizes and function were measured. Twenty-two patients in sinus rhythm served as the control group (SR). Complete visualization of the RA appendage was feasible in 90 patients with AF. Patients with AF had lower tricuspid annular excursion (p = 0.008) and larger RA chamber area (p = 0.0001) than patients in SR. In addition, RA appendage areas were larger (p <0.05) and RA ejection fraction and peak emptying velocities (both p <0.0001) were lower in patients with AF patients than in those in SR. Equivalent differences were found for the LA appendage. Six thrombi were found in the RA appendage and 11 thrombi in the LA appendage in AF patients. Spontaneous echo contrast was found in 57% and 66% in the right atrium and in the left atrium, respectively. AF patients with RA appendage thrombi had a larger RA area (p = 0.0001), and lower RA appendage ejection fraction and emptying velocities (both p = 0.0001) than patients without thrombi. Spontaneous echo contrast was detected in all patients with thrombi. Spontaneous echo contrast was the only independent predictor of RA (p = 0.03) and LA appendage thrombosis (p = 0.036). In conclusion, multiplane transesophageal echocardiography allows the assessment of RA appendage morphology and function. RA spontaneous echo contrast is the only independent predictor of RA appendage thrombosis.


Subject(s)
Atrial Appendage/diagnostic imaging , Atrial Fibrillation/diagnostic imaging , Echocardiography, Transesophageal , Thrombosis/diagnostic imaging , Adult , Aged , Blood Flow Velocity/physiology , Echocardiography, Doppler, Pulsed , Female , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Risk Factors , Stroke Volume/physiology , Ventricular Function, Left/physiology
4.
Am J Cardiol ; 83(12): 1633-7, 1999 Jun 15.
Article in English | MEDLINE | ID: mdl-10392867

ABSTRACT

Internal atrial defibrillation (IAD) is able to restore sinus rhythm in patients with chronic atrial fibrillation (AF) and failed external electrical and/or pharmacologic cardioversion. To assess whether cardiorespiratory and hemodynamic function improve after IAD, 35 patients were prospectively investigated during constant workload exercise by spiroergometry and Doppler echocardiography before IAD, and 1 day and 1 month after IAD. Oxygen uptake kinetics, ventilation, left atrial mechanical function, and pulmonary artery pressure were determined simultaneously at rest and during steady state. During the serial follow-up, 20 patients maintained sinus rhythm. The time interval for achieving the steady state (146 +/- 53 vs 132 +/- 42 seconds; p = 0.5) and the oxygen deficit (645 +/- 190 vs 670 +/- 174 ml; p = 0.7) were not different before and 1 day after IAD, but decreased significantly after 1 month (98 +/- 16 seconds, p = 0.01 and 487 +/- 72 ml, p = 0.02). Exercise pulmonary artery systolic pressures were 38 +/- 13 mm Hg before IAD, increased significantly to 46 +/- 11 mm Hg on day 1 (p = 0.03), and decreased below baseline values at 1 month to 31 +/- 12 mm Hg (p = 0.07). Peak A-wave velocities increased from 0.51 +/- 0.1 m/s after 1 day to 0.67 +/- 0.2 m/s after 1 month (p = 0.03). Restoration of sinus rhythm in patients with AF resistant to external electrical and/or pharmacologic cardioversion improves hemodynamic and cardiorespiratory function at daily activity exercise levels.


Subject(s)
Atrial Fibrillation/therapy , Electric Countershock , Hemodynamics , Oxygen Consumption , Atrial Fibrillation/physiopathology , Chronic Disease , Echocardiography, Doppler , Female , Humans , Male , Middle Aged , Prospective Studies
5.
Heart ; 81(2): 192-8, 1999 Feb.
Article in English | MEDLINE | ID: mdl-9922358

ABSTRACT

OBJECTIVE: To compare the value of current transthoracic echocardiographic systems and transoesophageal echocardiography for assessing left atrial appendage function and imaging thrombi. DESIGN: Single blind prospective study. Patients were first investigated by transthoracic echocardiography and thereafter by a second investigator using transoesophageal echocardiography. The feasibility of imaging the left atrial appendage, recording its velocities, and identifying thrombi within the appendage were determined by both methods. PATIENTS: 117 consecutive patients with a stroke or transient neurological deficit. SETTING: Tertiary cardiac and neurological care centre. RESULTS: Imaging of the complete appendage was feasible in 75% of the patients by transthoracic echocardiography and in 95% by transoesophageal echocardiography. Both methods were concordant for the detection of thrombi in 10 cases. Transoesophageal echocardiography revealed two additional thrombi. In one of these patients, transthoracic echocardiography was not feasible and in the other the thrombus had been missed by transthoracic examination. In patients with adequate transthoracic echogenicity, the specificity and sensitivity of detecting left atrial appendage thrombi were 100% and 91%, respectively. Recording of left atrial appendage velocities by transthoracic echocardiography was feasible in 69% of cases. None of the patients with a velocity > 0.3 m/s had left atrial appendage thrombi. In the one patient in whom transthoracic echocardiographic evaluation missed a left atrial appendage thrombus, the peak emptying velocity of the left atrial appendage was 0.25 m/s. CONCLUSIONS: A new generation echocardiographic system allows for the transthoracic detection of left atrial appendage thrombi and accurate determination of left atrial appendage function in most patients with a neurological deficit.


Subject(s)
Atrial Function, Left , Echocardiography, Transesophageal , Heart Atria/diagnostic imaging , Thromboembolism/diagnostic imaging , Adult , Aged , Echocardiography , Female , Heart Atria/physiopathology , Humans , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Single-Blind Method , Thromboembolism/physiopathology
6.
Am J Cardiol ; 81(12): 1446-9, 1998 Jun 15.
Article in English | MEDLINE | ID: mdl-9645895

ABSTRACT

Chronic atrial fibrillation (AF), which is refractory to external electrical direct current shock and/or pharmacologic cardioversion, may be successfully cardioverted using internal atrial defibrillation. To avoid unnecessary procedures, it is important to be able to predict which patients will revert to AF. Thirty-eight patients with chronic AF underwent successful internal atrial defibrillation and were followed for 6 months after restoration of sinus rhythm. Left atrial (LA) diameter, left ventricular ejection fraction, maximum LA appendage area, and peak emptying velocities of the LA appendage were analyzed to determine which of these factors were associated with recurrence of AF. Forty-nine percent of patients had a recurrence of AF within 6 months following internal atrial defibrillation. The preprocedural ejection fraction (mean +/- SD 59 + 14% vs 57 + 13%, p = 0.63), LA diameter (4.2 +/- 0.6 cm vs 4.5 +/- 0.6 cm, p = 0.16), and LA appendage area (5.0 +/- 1.5 cm2 vs 5.8 +/- 1.5 cm2, p = 0.13) did not differ significantly between patients who maintained sinus rhythm and those who had recurrence of AF. Peak emptying velocities of the LA appendage before cardioversion were significantly lower in patients with recurrence of AF compared with patients who maintained sinus rhythm (0.26 +/- 0.1 m/s vs 0.49 +/- 0.17 m/s, p = 0.001). A peak emptying velocity <0.36 had a sensitivity of 82% and a specificity of 83% for predicting recurrence of AF.


Subject(s)
Arrhythmia, Sinus , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/therapy , Electric Countershock , Aged , Echocardiography, Transesophageal/methods , Female , Humans , Male , Middle Aged , Predictive Value of Tests
8.
Heart ; 78(3): 250-4, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9391286

ABSTRACT

OBJECTIVE: To determine whether echocardiographic markers thromboembolic risk differ between patients with pure atrial flutter and patients with atrial flutter and intermittent atrial fibrillation. DESIGN: Patients with atrial flutter were followed up prospectively for 12 months to identify intermittent atrial fibrillation. After the follow up period, transthoracic and multiplane transoesophageal echocardiography were performed to assess left atrial chamber and appendage size, peak emptying velocities, and emptying fraction of the left atrial appendage. The presence of spontaneous echo contrast was also determined. SETTING: Tertiary cardiac care centre. PATIENTS: 20 consecutive patients with atrial flutter; 11 healthy subjects in sinus rhythm served as controls. RESULTS: Intermittent atrial fibrillation was documented in 11 patients by Holter monitoring or surface ECG; atrial fibrillation was not found in the other nine patients. Compared with the patients with pure atrial flutter, patients with atrial flutter and intermittent atrial fibrillation had larger left atrial chamber (mean (SD) 4.5 (0.6) v 3.8 (0.5) cm; 95% confidence interval 0.2 to 1.2; P = 0.01) and appendage areas (6.7 (2.2) v 4.8 (4.9) cm; 95% CI 0.4 to 3.5; P = 0.02), lower left atrial appendage emptying fractions (33 (11)% v 52 (11)%; 95% CI 8 to 29; P = 0.008), and also lower left atrial appendage emptying velocities (0.44 (0.21) v 0.79 (0.27) m/s; 95% CI 0.13 to 0.56; P = 0.005). In addition, a higher incidence of spontaneous echo contrast (11% v 36%) was observed in patients with atrial flutter and intermittent atrial fibrillation. CONCLUSIONS: Left atrial appendage function is depressed and spontaneous echo contrast more frequent in patients with atrial flutter and intermittent atrial fibrillation, as opposed to patients with pure atrial flutter. These data support the concept that patients with atrial flutter and intermittent atrial fibrillation have an increased risk of thromboembolic events and should therefore receive adequate anticoagulant treatment.


Subject(s)
Atrial Fibrillation/complications , Atrial Flutter/complications , Atrial Function, Left , Aged , Anticoagulants/therapeutic use , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/physiopathology , Atrial Flutter/diagnostic imaging , Atrial Flutter/physiopathology , Blood Flow Velocity , Echocardiography , Echocardiography, Transesophageal , Electric Countershock , Electrocardiography, Ambulatory , Female , Follow-Up Studies , Humans , Male , Prospective Studies , Risk Factors , Single-Blind Method , Statistics, Nonparametric , Thromboembolism/prevention & control
9.
Dtsch Med Wochenschr ; 122(6): 156-60, 1997 Feb 07.
Article in German | MEDLINE | ID: mdl-9081801

ABSTRACT

HISTORY AND CLINICAL FINDINGS: A 68-year-old woman was hospitalized because of fever and tiredness for 3 months. Her general condition was clearly impaired. She had a mild fever of 38.5 degrees C and on auscultation a 3/6 systolic murmur, maximal parasternally in the 3rd intercostal space, transmitted to the apex. There were distant râles over both lungs, the neck veins were distended and there was ankle oedema. INVESTIGATIONS: C-reactive protein was raised to 17.3 mg/dl (normal up to 0.9 mg/dl), WBC count 19,300/microliter. beta-haemolysing streptococcus (S. agalactiae) was grown in the blood culture. The ECG showed sinus tachycardia (rate of 98/min) and transthoracic echocardiography demonstrated a small pericardial, enlarged ventricles, marked mitral regurgitation and a large vegetation on the posterior mitral leaflet, as well as a 3 x 4 cm mass in the posterior wall of the ventricle, originating from the posterior mitral valve ring and communicating with the vegetation on the mitral valve. The posterior mitral leaflet was perforated. TREATMENT AND COURSE: As endocarditis of the mitral valve with a complicated course was suspected-abscess of the posterior mitral valve ring and septic myocardial aneurysm with associated pericarditis and haemodynamically insignificant effusion-she was transferred to the intensive care unit where she died suddenly of circulatory arrest only 30 min after transfer. Autopsy confirmed the echocardiographic findings. CONCLUSION: Paravalvular abscess in the course of mitral valve endocarditis is rare, but should be looked for at transthoracic echocardiography so that any necessary surgical intervention can be undertaken early.


Subject(s)
Endocarditis, Bacterial/diagnosis , Heart Aneurysm/diagnosis , Mitral Valve Insufficiency/diagnosis , Sepsis/diagnosis , Aged , Autopsy , Electrocardiography , Endocarditis, Bacterial/pathology , Female , Heart Aneurysm/pathology , Humans , Mitral Valve Insufficiency/pathology , Myocardium/pathology , Sepsis/pathology
10.
J Am Coll Cardiol ; 29(1): 131-8, 1997 Jan.
Article in English | MEDLINE | ID: mdl-8996305

ABSTRACT

OBJECTIVES: The purpose of this prospective study was to assess left atrial chamber and appendage function after internal atrial defibrillation of atrial fibrillation and to evaluate the time course of recovery. BACKGROUND: External cardioversion of atrial fibrillation may result in left atrial appendage dysfunction ("stunning") and may promote thrombus formation. In contrast to external cardioversion, internal atrial defibrillation utilizes lower energies; however, it is unknown whether the use of lower energies may avoid stunning of the left atrial appendage. METHODS: Transesophageal and transthoracic echocardiography were performed in 20 patients 24 h before and 1 and 7 days after internal atrial defibrillation to assess both left atrial chamber and appendage function. Transthoracic echocardiography was again performed 28 days after internal atrial defibrillation to assess left atrial function. The incidence and degree of spontaneous echo contrast accumulation (range 1+ to 4+) was noted, and peak emptying velocities of the left atrial appendage were measured before and after internal atrial defibrillation. To determine left atrial mechanical function, peak A wave velocities were obtained from transmitral flow velocity profiles. RESULTS: Sinus rhythm was restored in all patients. The mean +/- SD peak A wave velocities increased gradually after cardioversion, from 0.47 +/- 0.16 m/s at 24 h to 0.61 +/- 0.13 m/s after 7 days (p < 0.05) and 0.63 +/- 0.13 m/s after 4 weeks. Peak emptying velocities of the left atrial appendage were 0.37 +/- 0.16 m/s before internal atrial defibrillation, decreased significantly after internal atrial defibrillation to 0.23 +/- 0.1 m/s at 24 h (p < 0.01) and then recovered to 0.49 +/- 0.23 m/s (p < 0.01) after 7 days. The corresponding values for the degree of spontaneous echo contrast were 1.2 +/- 1.2 before internal atrial defibrillation versus 2.0 +/- 1.0 (p < 0.01) and 1.1 +/- 1.3 (p < 0.01) 1 and 7 days after cardioversion, respectively. One patient developed a new thrombus in the left atrial appendage, and another had a thromboembolic event after internal atrial defibrillation. CONCLUSIONS: Internal atrial defibrillation causes depressed left atrial chamber and appendage function and may result in the subacute accumulation of spontaneous echo contrast and development of new thrombi after cardioversion. These findings have important clinical implications for anticoagulation therapy before and after low energy internal atrial defibrillation in patients with atrial fibrillation.


Subject(s)
Atrial Fibrillation/therapy , Atrial Function, Left/physiology , Echocardiography, Transesophageal , Electric Countershock/methods , Anticoagulants/therapeutic use , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/physiopathology , Blood Flow Velocity/physiology , Echocardiography , Female , Humans , Male , Middle Aged , Prospective Studies , Risk Factors , Thromboembolism/epidemiology , Time Factors
12.
Heart ; 75(4): 377-83, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8705765

ABSTRACT

OBJECTIVE: To analyse profiles of coronary artery flow velocity at rest in patients with aortic stenosis and to determine whether changes of the coronary artery flow velocities are related to symptoms in patients with aortic stenosis. DESIGN: A prospective study investigating the significance of aortic valve area, pressure gradient across the aortic valve, systolic left ventricular wall stress index, ejection fraction, and left ventricular mass index in the coronary flow velocity profile of aortic stenosis; and comparing flow velocity profiles between symptomatic and asymptomatic patients with aortic stenosis using transoesophageal Doppler echocardiography to obtain coronary artery flow velocities of the left anterior descending coronary artery. SETTING: Tertiary referral cardiac centre. PATIENTS: Fifty eight patients with aortic stenosis and 15 controls with normal coronary arteries. RESULTS: Adequate recordings of the profile of coronary artery flow velocities were obtained in 46 patients (79%). Left ventricular wall stress was the only significant haemodynamic variable for determining peak systolic velocity (r = -0.83, F = 88.5, P < 0.001). The pressure gradient across the aortic valve was the only contributor for explaining peak diastolic velocity (r = 0.56, F = 20.9, P < 0.001). Controls and asymptomatic patients with aortic stenosis (n = 12) did not differ for peak systolic velocity [32.8 (SEM 9.7) v 27.0 (8.7) cm/s, NS] and peak diastolic velocity [58.3 (18.7) v 61.9 (13.5) cm/s, NS]. In contrast, patients with angina (n = 12) or syncope (n = 8) had lower peak systolic velocities and higher peak diastolic velocities than asymptomatic patients (P < 0.01). Peak systolic and diastolic velocities were -7.7 (22.5) cm/s and 81.7 (17.6) cm/s for patients with angina, and -19.5 (22.3) cm/s and 94.0 (20.9) cm/s for patients with syncope. Asymptomatic patients and patients with dyspnoea (n = 14) did not differ. CONCLUSIONS: Increased pressure gradient across the aortic valve and enhanced systolic wall stress result in characteristic changes of the profile of coronary flow velocities in patients with aortic stenosis. Decreased or reversed systolic flow velocities are compensated by enhanced diastolic flow velocities, particularly in patients with angina and syncope. This characteristic pattern of the profile of coronary artery flow velocities in patients with angina or syncope may be useful for differentiating those patients from asymptomatic patients.


Subject(s)
Aortic Valve Stenosis/physiopathology , Coronary Circulation/physiology , Echocardiography, Doppler , Echocardiography, Transesophageal , Aged , Angina Pectoris/diagnostic imaging , Angina Pectoris/etiology , Angina Pectoris/physiopathology , Aortic Valve Stenosis/complications , Aortic Valve Stenosis/diagnostic imaging , Blood Flow Velocity/physiology , Female , Humans , Male , Prospective Studies , Syncope/diagnostic imaging , Syncope/etiology , Syncope/physiopathology
13.
J Heart Valve Dis ; 5(1): 31-4, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8834722

ABSTRACT

BACKGROUND AND AIMS: Syncope is a serious complication of aortic stenosis. The aim of this study was to determine whether hemodynamic parameters are useful for estimating the risk of syncope in aortic stenosis. METHODS: In 43 patients with aortic stenosis, cardiac catheterization and echocardiography were performed to measure the pressure gradient across the aortic valve, the aortic valve area, left ventricular mass index, systolic left ventricular wall stress and peak systolic coronary artery flow velocities. Hemodynamic parameters were correlated with syncope and the accuracy of those parameters for determining the risk of syncope were assessed. RESULTS: Ten out of 43 patients experienced syncope. The highest correlation with syncope was found for systolic left ventricular wall stress (R = 0.74, p < 0.001). In descending order of correlation were peak systolic coronary artery flow velocity (R = 0.68, p = 0.002), the pressure gradient across the aortic valve (R = 0.62, p = 0.01) and the aortic valve area (R = 0.43, p = 0.03). Left ventricular mass index was not significantly correlated with syncope. Multivariate analysis revealed systolic left ventricular wall stress to be the only factor contributing to determining syncope (F-to-remove: 47.8). A discriminative value of > 225 dyn/cm-2 x 103 for left ventricular wall stress identified patients with a history of syncope with a specificity of 97% and a sensitivity of 90%. CONCLUSIONS: Syncope in aortic stenosis is closely correlated to increased left ventricular wall stress and attenuated, peak systolic coronary flow velocities. Cut off values may be used to identify patients with an increased risk of syncope.


Subject(s)
Aortic Valve Stenosis/complications , Syncope/etiology , Aged , Aortic Valve/physiopathology , Aortic Valve Stenosis/physiopathology , Blood Flow Velocity/physiology , Cardiac Catheterization , Coronary Circulation/physiology , Echocardiography , Echocardiography, Doppler , Female , Hemodynamics/physiology , Humans , Male , Middle Aged , Risk Factors , Syncope/physiopathology , Ventricular Function, Left/physiology
14.
Z Kardiol ; 81(11): 627-35, 1992 Nov.
Article in German | MEDLINE | ID: mdl-1471400

ABSTRACT

The normal leakage flow in modern technical heart valve prostheses can be visualized by color-coded Doppler-echocardiography, provided that an adequate ultrasonic image quality can be achieved. Sometimes it may be difficult, however, to distinguish such a normal leakage flow from pathological regurgitation. We therefore mounted new specimens of five different types of prostheses (Bjørk-Shiley monostrut, Medtronic-Hall, Omnicarbon, Saint Jude Medical, Duromedics) into an invitro model, where the leakage flows could directly be visualized as emerging water jets. When the system was completely filled, the jets could also be registered by two-dimensional Doppler-echocardiography. For each valve, characteristic patterns for the localization of the principal jets were found. Besides the relative broad central jet in the Medtronic-Hall valve, all other jets arose mainly at the ring. They were detected at the hinges or the basis of the larger struts, respectively, and with asymmetrical mono-disc valves at the side of the smaller opening. The length and the orientation of the jets were found to change significantly with minimal variations of the position of the closing discs. This variability could be confirmed, when in a separate model the overall leakage flows were repeatedly measured. For patient examinations it seems useful to refer mainly to the localization of the jet origins. The comparison with reference values of jet-dimensions in Doppler images will rarely enable the examiner to distinguish between normal and pathological jets.


Subject(s)
Echocardiography, Doppler/instrumentation , Heart Valve Prosthesis , Hemodynamics/physiology , Image Processing, Computer-Assisted/instrumentation , Models, Cardiovascular , Humans , Prosthesis Design , Prosthesis Failure , Reference Values
15.
Z Kardiol ; 80(7): 441-8, 1991 Jul.
Article in German | MEDLINE | ID: mdl-1926989

ABSTRACT

In a flow model the effective orifice areas (Ae) of 17 mechanical heart valve prostheses were determined. We measured the Ae-values of several sizes of three types of mechanical prostheses (Medtronic-Hall, St. Jude Medical, and Omnicarbon) under quasi-steady flow conditions using the continuity equation: Ae = flow/maximal transprosthetic velocity. The flow through the model could be determined exactly by directly measuring the decreasing fluid level within the feed tank, while the maximal velocities were calculated from CW-Doppler echocardiographic spectra. It was found that 1) over a range of 200-800 cm3/s Ae was constant for all prostheses and 2) in small aortic prostheses the Ae could be determined with only little scattering of the obtained values, while in large mitral prostheses there was a considerable variation within the results of repeated investigations. For example, in the 21- and 31-Omnicarbon-valves mean values of Ae were calculated as 1.41 and 4.03 cm2, respectively, with standard deviations of 0.05 and 0.49 cm2 as a result of about 70 single calculations in each valve. 3) The absolute values of Ae were smaller than those of comparable in vitro studies based on the Gorlin formula. We conclude that the effective orifice areas of prosthetic heart valves can be easily determined in a flow model by the combination of flow and Doppler echocardiographic measurements. As determinations are based on the same principle, the obtained values should clinically be referred to patients where the corresponding continuity equation for pulsatile flow is used as Ae = stroke volume/time integral of the maximal transvalvular velocity.


Subject(s)
Aortic Valve/anatomy & histology , Echocardiography, Doppler , Heart Valve Prosthesis , Mitral Valve/anatomy & histology , Aortic Valve/physiology , Blood Flow Velocity , Humans , Mitral Valve/physiology , Models, Cardiovascular , Prosthesis Design
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