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V Hombach

Publications and source records attributed to V Hombach.

At least 91 records · Page 5Linked to original sources
PubMed1995

Quantification of mitral regurgitation--comparison of the proximal flow convergence method and the jet area method.

A total of 92 patients with mitral regurgitation (age 63 +/- 13 years, 51 men, 41 women), quantified by angiography, were studied using color-flow Doppler imaging of isovelocity surface areas in the flow convergence region proximal to the regurgitant orifice (PISAs) and of the regurgitant jet in the left atrium. The PISA radii for the flow velocities (aliasing borders) of 28 and 41 cm/s, jet area, jet length, and relation of jet area to left atrial area were measured. A proximal flow convergence region was imaged in 98% (85%) of all patients for a flow velocity of 28 (41) cm/s. A regurgitant jet could be visualized in all patients. The PISA radii for both flow velocities correlated more closely with the angiographic grade (rSp = 0.79 for both flow velocities) than the jet area (rSp = 0.43), jet length (rSp = 0.39), and relation of jet area to left atrial area (rSp = 0.37). A correct differentiation of grade I-II from grade III-IV mitral regurgitation was provided in 95% of the patients by the proximal flow convergence method for both flow velocities and in up to 78% of the patients by the jet area method using the uncorrected jet area. The PISA radii correlated weakly with the parameters from the regurgitant jet (r = 0.5-0.58). It can be concluded that the proximal flow convergence method and the jet area method reach comparable sensitivity for the detection of mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Recombinant interleukin-2 acts like a class I antiarrhythmic drug on human cardiac sodium channels.

Human recombinant interleukin-2 (rIL-2) was bath-applied to isolated human cardiocytes while sodium currents were triggered and registered using the whole-cell recording technique. In the presence of the cytokine the sodium currents were reversibly blocked, 50% peak current reduction occurring at a concentration of 500 U/ml. The current-voltage relationship was not affected, but the steady-state inactivation curve was not affected, but the steady-state inactivation curve was shifted in the negative direction by 15 mV. When 35% of the sodium current was blocked the time constant of recovery from block at -135 mV was in the range of 63 +/- 27 ms. Use dependence was observed only at stimulation frequencies above 4 Hz. Addition of a polyclonal anti-IL-2 antibody to the extracellular solution prevented all of the above effects, while incubation of the cells with a function-blocking monoclonal anti-IL-2 receptor antibody had no influence on the described rIL-2 action. In contrast to rIL-2, recombinant tumor necrosis factor alpha (rTNF-alpha) did not affect the sodium currents. It is concluded that rIL-2 acts like a class I antiarrhythmic drug on human cardiac sodium channels. This might explain some of its proarrhythmic side effects when given intravenously in high doses.

Antibodies↗
PubMed1995

A prescreening system for potential antiproliferative agents: implications for local treatment strategies of postangioplasty restenosis.

BACKGROUND: Recent advances in the understanding of the biology of restenosis indicate that it is predominantly caused by a multifactorial stimulation of smooth muscle cell proliferation. The aim of this study was to investigate the in vitro effect of five potential antiproliferative agents on smooth muscle cells from human atherosclerotic femoral arteries. METHODS AND RESULTS: Primary stenosing plaque material of 24 patients (aged 63 +/- 14 years) and restenosing plaque material of 7 patients (aged 65 +/- 9 years) was selectively extracted from femoral arteries by the Simpson atherectomy device. Cells were isolated by enzymatic disaggregation and identified as smooth muscle cells by positive reaction with smooth muscle alpha-actin. Dalteparin sodium (0.001-100 anti-Xa units/ml), cyclosporine A (0.005-500 micrograms/ml), colchicine (0.00004-4 pg/ml), etoposide (0.002-200 micrograms/ml), and doxorubicin (0.0005-50 micrograms/ml) were added to the cultures. Six days after seeding, cells were trypsinized and cell number was measured by a cell counter. All five agents tested exhibited a significant inhibition of smooth muscle cell proliferation (P < 0.001). After an incubation time of 48 h, the cytoskeletal components, alpha-actin, vimentin, and microtubules were investigated. At peak concentrations, all five tested agents except dalteparin sodium caused severe damage to the cytoskeleton. CONCLUSIONS: All five potential antiproliferative agents exhibited a significant inhibition of smooth muscle cell proliferation. The development of new intravascular delivery systems may open the way for local antiproliferative treatment strategies in interventional cardiology.

Actins↗
PubMed1995

A coronary porcine organ culture system for studies of postangioplasty cell proliferation.

BACKGROUND: Restenosis after angioplasty is generally considered to be caused mainly by an increased proliferation of smooth muscle cells, but recently this theory has been questioned. METHODS: Fresh hearts of 25 pigs were obtained and the left anterior descending coronary arteries carefully prepared, cut into segments and treated with a 3 mm standard balloon catheter for 60 s with 3, 6, 9 and 12 bar. Immediately after angioplasty the specimens were cultured in a mixture of WM/F-12, supplemented with 15% fetal calf serum. RESULTS: After staining with a modified Verhoeff-van Gieson technique, intimal wall thickening was analysed with a computerized morphometric system. After 14 days in culture, angioplasty with 6, 9 and 12 bar resulted in a significant (P < 0.05) increase of neointimal thickening. After 21 days, a significant increase of neointimal thickening was seen after ballooning with 3, 9 or 12 bar (P < 0.05). After 28 days angioplasty with 3 or 6 bar showed a dose-dependent increase of neointima, which was not further increased after ballooning with 9 or 12 bar. Significance was reached after ballooning with 6, 9 and 12 bar (P < 0.05). Smooth muscle cells were identified with a monoclonal antibody against smooth muscle alpha-actin. Endothelial cells were identified using an anti-human von Willebrand factor. To determine the number of cells undergoing DNA synthesis, bromodeoxyuridine, a thymidine analogue, was added to the culture media 18 h before fixation. It was detected with a monoclonal antibody, with a biotinylated horse-anti-mouse antibody as secondary antibody. After 4 and 7 days in culture bromodeoxyuridine-positive cells were observed, indicating an early proliferative response after angioplasty. CONCLUSIONS: The coronary organ culture model offers opportunities for investigations of complex cellular events that are considered important in the development of restenosis. The data reported emphasize the importance of an early proliferative response of smooth muscle cells after coronary angioplasty, resulting in a significant neointimal thickening.

Angioplasty, Balloon↗
PubMed1995

[Assessment of severity of mitral insufficiency--value of various color Doppler echocardiographic methods].

A total of 79 patients with mitral regurgitation (age 62 +/- 11 years, 45 men, 34 women) quantified by angiography was studied using color-Doppler imaging of isovelocity surface areas in the flow convergence region proximal to the regurgitant orifice (PISAs), of the jet cross-section at the level of the regurgitant orifice and of the regurgitant jet in the left atrium. The PISA-radii for the flow velocities (aliasing borders) of 28 and 41 cm/s, the cross-sectional jet area and the jet length, and relation of jet area to left atrial area were measured. The sensitivity for the detection of mitral regurgitation was at least 97% for the color-Doppler methods investigated in these patients in which a sufficient imaging was obtained. However, a sufficient imaging of the flow convergence region and the jet cross-section was not possible in about 5% of all patients. The PISA-radii for both flow velocities and the cross-sectional jet area correlated more closely with the angiographic grade (rSp = 0.79-0.80, p < 0.001) than the jet area (rSp = 0.39, p < 0.001), jet length (rSp = 0.37, p < 0.001), and relation of jet area to left atrial area (rSp = 0.31, p < 0.01) did. A correct differentiation of grades I to II from grades III to IV mitral regurgitation was provided in 93-95% of patients by the proximal flow convergence and by the cross-sectional jet area method and, at most, in 76% of the patients by the jet area method using the uncorrected jet area.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Reduction of exercise-induced myocardial perfusion defects by isosorbide-5-nitrate: assessment using quantitative Tc-99m-MIBI-SPECT.

BACKGROUND: Although nitrates were introduced more than 100 years ago and have been used for the treatment of angina pectoris, there are still some open questions concerning the mechanism of their action on myocardial ischemia. There are also insufficient data regarding the influence of any anti-ischemic medication on the results of myocardial perfusion scintigraphy. METHODS: To assess the influence of a mononitrate, 30 patients with stable angina pectoris, coronary stenosis > or = 70% and normal left ventricular function were examined using quantitative Tc-99m-MIBI exercise-single photon emission computed tomography (SPECT). On the same day, 5 h after a randomized double-blind dose of 60 mg sustained-release isosorbide-5-nitrate or placebo, SPECT was repeated with identical stress protocol. The results were analyzed using a semi-automatic polar coordinate program that allows definition of areas with significant decreased blood flow expressed as a percentage of standard vessel area. RESULTS: In the vessel areas with the largest perfusion defects, the mean defect size decreased after isosorbide-5-nitrate from 38.2 +/- 31.0% to 29.1 +/- 33.8% (reduction by 24%; P < 0.05) and increased from 35.2 +/- 27.6% to 36.6 +/- 27.4% after placebo (increase by 4%; P = NS). The difference between defect size changes was also significant (P < 0.05). CONCLUSION: Acute administration of sustained-release isosorbide-5-nitrate significantly reduces the size of exercise-induced perfusion defects as assessed using quantitative Tc-99m-MIBI-SPECT.

Adult↗
PubMed1995

[Recurrent stenosis following coronary angioplasty. Clinical, cell biological and molecular aspects].

Percutaneous transluminal coronary angioplasty by balloon dilatation (PTCA) has proved to be the standard procedure for non-operative removal of coronary artery stenoses. Since the initial description and application by Andreas Grüntzig, the results of this procedure are excellent with an acute success rate of 90-96%, a rate of severe acute complications of 1% and less, and a procedure-related death rate below 1%, mainly due to considerable technical improvements and greater experience of the interventional cardiologists. On the other hand, the restenosis rate following PTCA could not be significantly lowered. In recent years a number of alternative angioplasty devices has been developed aimed at-among other indications-reducing the restenosis rate following PTCA by a "less traumatic" vessel angioplasty. These include radiofrequency angioplasty (RFCA), high frequency rotational angioplasty (HFRCA), excimer-laser angioplasty (ELCA), directional atherectomy (DCA), as well as implantation of intravascular stents. Based on more or less extensive experiences from the literature, the aim at lowering the recurrency rate by the latter procedures has been missed, despite the fact that particularly ELCA and HFRCA were used to reduce stenoses in lesions unsuitable for balloon catheter dilatation. There is a trend of lowering the recurrence rate with the implantation of coronary stents. The benefit of this procedure, however, is at the expense of an increased rate of acute stent thrombosis and by local acute bleeding problems quite often requiring surgical repair. The cellular biological mechanisms following balloon angioplasty are only partially understood. Among these are a number of interactive processes like cell adhesion, coagulation, vascular contraction, cell migration, cell proliferation, and synthesis of extracellular matrix. In this respect, migration and proliferation of smooth muscle cells represent a key process for the development of restenosis. In addition, endothelial denudation represents a stimulus for migration and proliferation of smooth muscle cells. Rapid and efficient reendothelialization may counteract this process. Recent progress of modern biology has provided new concepts and methodological tools for the molecular analysis of vascular remodeling. It has been shown that specialized cellular functions such as proliferation, migration, and production of extracellular matrix can be mediated by growth factors such as platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF) or transforming growth factor-beta (TGF-beta).(ABSTRACT TRUNCATED AT 400 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1995

[Three AV-nodal pathways in a patient with atypical AV-nodal reentry tachycardia].

In a female patient with paroxysmal AV nodal reentrant tachycardias the electrophysiological study revealed three AV nodal pathways. During atrial extrastimulation a sudden AH interval prolongation of more than 50 ms ("break" phenomenon) was observed twice at one basic cycle length. During ventricular extrastimulation a sudden prolongation of the AH interval of the anterograde AV nodal conduction of the induced echo beats was recorded. Three AV nodal pathways were thus present. The atypical form of AV nodal reentrant tachycardia was induced, showing a varying cycle length (290-340 ms). After radiofrequency catheter ablation of the fast conducting beta-pathway, another tachycardia was initiated, now showing a constant cycle length, using the two remaining, more slowly conducting alpha-pathways. One of these was eliminated in another ablation procedure.

Adult↗
PubMed1995

Cyclosporine A stimulates endothelin release.

Administration of cyclosporine A is often associated with the development of renal dysfunction and hypertension. Because recent data provide evidence that endothelin (ET) might be involved in mediating cyclosporine-associated cardiovascular and renal side effects, the present study aimed to investigate the influence of cyclosporine A on ET release from cultured smooth-muscle cells and whether ET plasma concentrations are elevated in cyclosporine-treated patients. Addition of cyclosporine A to the medium of cultured human smooth-muscle cells, isolated from atherosclerotic iliac arteries, induced a dose-dependent increase in ET release. ET plasma levels were significantly elevated in cyclosporine-treated patients after bone marrow transplantation, compared to control groups. These data suggest that enhanced ET release might be involved in mediating the cyclosporine-associated side effects.

Cells, Cultured↗
PubMed1995

Management of unstable angina in patients over 75 years old.

BACKGROUND: Although there have been reports of successful percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) in elderly patients, few data are available on the optimal management of unstable angina in such patients. This study was therefore designed to identify the preferred revascularization strategy in patients with unstable angina over 75 years of age. METHODS: Early and late results were evaluated for patients over 75 years with unstable angina undergoing PTCA (n = 51) or CABG (n = 53). The two groups were comparable with respect to age, sex distribution, clinical manifestation of symptoms, left ventricular ejection fraction and accompanying non-cardiac diseases. In the CABG group, significantly more patients had left main coronary artery stenosis (13 and 2%, respectively). RESULTS: Both PTCA and CABG treatment showed similar procedural success rates (91 and 94% respectively) and hospital mortality rates (4 and 6% respectively). Procedural complications were comparable regarding Q-wave myocardial infarction, stroke, renal failure and vascular complications. Patients undergoing CABG received significantly more blood transfusions than those undergoing PTCA (17 and 2% respectively). During follow-up, the mortality rate was comparable in both groups (4% with CABG and 8% with PTCA), but significantly fewer patients in the CABG group developed unstable angina (8 versus 21% in the PTCA group), fewer patients were readmitted to hospital for cardiac reasons (CABG group 17%, PTCA group 31%) and fewer patients needed repeat coronary interventions (CABG group 4%, PTCA group 18%). CONCLUSION: Both PTCA and CABG were comparable with regard to short- and long-term mortality, but CABG treatment was favourable with regard to clinical symptoms, readmission to hospital and repeat coronary interventions.

Age Factors↗
PubMed1994

Corticosteroid agents inhibit proliferation of smooth muscle cells from human atherosclerotic arteries in vitro.

We studied the in vitro effect of steroid agents on smooth muscle cells from human atherosclerotic arteries. Recent advances in the understanding of the biology of restenosis indicate that restenosis is predominantly caused by a multifactorial stimulation of smooth muscle cell proliferation. Primary stenosing plaque material of 24 patients (aged 63 +/- 14 years) and restenosing plaque material of 7 patients (aged 65 +/- 9 years) was selectively extracted from femoral arteries by the Simpson atherectomy device. Cells were isolated by enzymatic disaggregation and identified as smooth muscle cells by positive reaction with smooth muscle alpha-actin. The steroid agents prednisolone (0.0075-750 micrograms/ml), hydrocortisone (0.0125-1250 micrograms/ml), and dexamethasone (0.0004-40 micrograms/ml) were added to the cultures. Six days after seeding the cells were trypsinized and the cell number was measured by a cell counter. All three steroid agents exhibited a significant antiproliferative effect on smooth muscle cell proliferation. At high concentrations of hydrocortisone, cytoskeletal elements of smooth muscle cells such as actin, microtubules, and vimentin, were largely altered. Our data indicate that the proliferation of smooth muscle cells from human atherosclerotic arteries in vitro can be inhibited by steroid agents and thus may open the way for local post-angioplasty treatment strategies.

Actins↗
PubMed1994

Increased brain natriuretic peptide and atrial natriuretic peptide plasma concentrations in dialysis-dependent chronic renal failure and in patients with elevated left ventricular filling pressure.

Brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) plasma concentrations were measured in patients with dialysis-dependent chronic renal failure and in patients with coronary artery disease exhibiting normal or elevated left ventricular end-diastolic pressure (LVEDP) (n = 30 each). Blood samples were obtained from the arterial line of the arteriovenous shunt before, 2 h after the beginning of, and at the end of hemodialysis in patients with chronic renal failure. In patients with coronary artery disease arterial blood samples were collected during cardiac catheterization. BNP and ANP concentrations were determined by radioimmunoassay after Sep Pak C18 extraction. BNP and ANP concentrations decreased significantly (P < 0.001) during hemodialysis (BNP: 192.1 +/- 24.9, 178.6 +/- 23.0, 167.2 +/- 21.8 pg/ml; ANP: 240.2 +/- 28.7, 166.7 +/- 21.3, 133.0 +/- 15.5 pg/ml). The decrease in BNP plasma concentrations, however, was less marked than that in ANP plasma levels (BNP 13.5 +/- 1.8%, ANP 40.2 +/- 3.5%; P < 0.001). Plasma BNP and ANP concentrations were 10.7 +/- 1.0 and 60.3 +/- 4.0 pg/ml in patients with normal LVEDP and 31.7 +/- 3.6 and 118.3 +/- 9.4 pg/ml in patients with elevated LVEDP. These data demonstrate that BNP and ANP levels are strongly elevated in patients with dialysis-dependent chronic renal failure compared to patients with normal LVEDP (BNP 15.6-fold, ANP 2.2-fold, after hemodialysis; P < 0.001) or elevated LVEDP (BNP 6.1-fold, ANP 2.0-fold, before hemodialysis; P < 0.001), and that the elevation in BNP concentrations was more pronounced than that in ANP plasma concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The effect of LDL apheresis on progression of coronary artery disease in patients with familial hypercholesterolemia. Results of a multicenter LDL apheresis study.

This study investigated the effect of extracorporal lipid-lowering therapy by low-density lipoprotein (LDL) apheresis on coronary artery disease in a population characterized by early development and rapid progression of atherosclerosis. We treated 32 patients aged between 15 and 63 years with drug-refractory familial hypercholesterolemia, treated once a week by immuno-specific LDL apheresis for 3 years in a controlled prospective and non-randomized trial; 25 patients (14 females and 11 males) completed the study. Noninvasive data were obtained by physical examination, 12-lead ECG and exercise testing. Invasive cardiological data were obtained by cardiac catheterization according to a standardized protocol in four cardiological centers. Left ventricular ejection fraction was calculated using planimetry. Coronary stenoses were measured quantitatively in 23 defined coronary segments by a panel of four investigators with an electronic digital caliper. In addition, overall coronary atherosclerosis was visually qualified. Final decisions on a classification into one of three groups (regression, no change, progression) of coronary atherosclerosis were based on panel consensus. Six cardiac events occurred throughout the study: percutaneous transluminal coronary angioplasty in one patient, coronary bypass grafting in three and two deaths. Statistical analysis of exercise testing yielded no significant change for maximum power and work capacity during the study period. Hemodynamic data revealed no significant change; mean ejection fraction was calculated as 65.8 +/- 15.9% at study entry and 67.0 +/- 12.7% at completion. Quantitative measurement of 111 circumscribed coronary stenoses showed a mean stenosis degree of 45 +/- 26% at entry cineangio-film and 43 +/- 22% at final cineangio-film demonstrating no significant change.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Characterization of the sodium currents in isolated human cardiocytes.

The whole-cell recording technique was used to register Na+ currents from 403 atrial cardiocytes isolated from 80 human biopsies. With intracellular [Na+] ([Na+]i) raised to 70 mM, and at physiological extracellular [Na+] ([Na+]e, 145 mM) and room temperature, the Na+ currents were small enough for the error of the voltage clamp not to exceed 2 mV (series resistances 0.4-2 M omega). The threshold potential of the Na+ current was -64.0 +/- 7.7 mV. The peak amplitude was at -30.0 +/- 6.2 mV. The time course of fast inactivation was satisfactorily described with a single exponential. The time constant of inactivation was 2.0 ms at -55 mV and asymptotically approached 0.2 ms at positive membrane potentials. The steady-state inactivation curve was well fitted by a single Boltzmann distribution. Increasing the prepulse duration from 32 to 512 ms shifted the inflexion point of the curve from -61.7 +/- 6.4 to -72.2 +/- 2.6 mV. The time course of slow inactivation was also well described by a single exponential, the time constant ranging from 76.1 +/- 29.3 ms at -115 mV to 18.6 +/- 7.8 ms at -55 mV. Fitting the time course of recovery from inactivation required two time constants. At a recovery potential of -135 mV these were 1.6 +/- 0.2 and 8.6 +/- 2.9 ms and 15.9 +/- 9.4 and 53.2 +/- 33.3 ms at -95 mV. A 50% block of the Na+ currents was achieved by tetrodotoxin at 10 microM. It is concluded that the properties of human cardiac Na+ channels are similar to those of the juvenile Na+ channels of human skeletal muscle.

Heart Atria↗
PubMed1994

Improved detection of transient myocardial ischemia by a new lead combination: value of bipolar lead Nehb D for Holter monitoring.

The investigations of ST-segment changes by Holter monitoring demonstrate asymptomatic and symptomatic episodes of myocardial ischemia, which may occur during daily activities. One factor, which is of great importance for the detection of silent myocardial ischemia during ambulatory monitoring, is the combination of the leads. Former studies showed that the analysis of two channels alone may not adequately detect silent myocardial ischemia. We therefore used a three-channel ambulatory ECG monitoring system with a new lead combination. The Holter monitoring results were correlated with the distribution of coronary stenosis detected by coronary angiography. In 54 patients with single coronary vessel disease and ischemic ST-segment depressions during exercise testing, standard Holter lead combination CM2/CM5 was extended by a bipolar Nehb D-like lead. Lead combination CM2/CM5 identified 23 patients (43%) with ST-segment depressions (total number of ischemic episodes = 372). Additional Nehb D-like lead identified 30 patients (55%) with ST-segment depressions (total number of ischemic episodes = 1048). The combination of leads CM2/CM5 and Nehb D raised the number of patients with documented ST-segment depressions to 33 of 54 (61%). Lead Nehb D showed the highest sensitivity for the detection of inferior wall ischemia (stenosis of the right coronary artery); nevertheless, this lead may not be regarded as specific for ST-segment alterations only caused by inferior wall ischemia. The correlation of ischemic ST-segment depressions during exercise testing (classified as anterior, inferior, or anterior and inferior type of ischemia) and documented ST-segment changes in the different Holter leads underline these results.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angiography↗
PubMed1994

Systolic ventricular function in acute hypothyroidism: a study using Doppler echocardiography.

The influence of thyroid state on left ventricular systolic function was studied in 11 patients (5 men, 6 women, aged 20-55 years) without cardiac disease, who had undergone total thyroidectomy and radioiodine treatment for thyroid cancer before. Pulsed-wave Doppler echocardiographic measuring of aortic blood flow and two-dimensional/time-motion (2D/M-mode) echocardiography were performed on two occasions once while the patients were mildly hyperthyroid on thyroxine replacement therapy and once when they were hypothyroid. During hypothyroidism left ventricular end-diastolic diameter decreased from 48 +/- 5 mm to 46 +/- 5 mm (p < 0.05). The diameter of the aortic ring, the left ventricular end-systolic diameter, the thickness of the interventricular septum and posterior wall, and fractional shortening did not differ significantly between the two studies. The following parameter of aortic blood flow changed significantly when passing from the hyperthyroid to the hypothyroid state: peak velocity (0.86 +/- 0.15 m/s versus 0.72 +/- 0.15 m/s, p < 0.01); mean velocity (0.49 +/- 0.08 m/s versus 0.44 +/- 0.08 m/s, p < 0.01); time- velocity integral (14.1 +/- 3.0 cm versus 12.3 +/- 3.1 cm, p < 0.05); stroke volume (43.0 +/- 9.7 ml versus 35.2 +/- 8.2 ml, p < 0.05); and preejection period (124 +/- 23 ms versus 147 +/- 21 ms, p < 0.01). Peak acceleration, mean acceleration, acceleration time and left ventricular ejection time did not change when the thyroid state was altered. It is concluded that left ventricular contractile function was not affected by acute hypothyroidism.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Doppler echocardiographic evaluation of left ventricular diastolic function in acute hypothyroidism.

OBJECTIVE: Left ventricular diastolic dysfunction is an important cause of symptomatic heart failure. Previous studies suggest that thyroid dysfunction affects left ventricular diastolic function but the underlying mechanisms remain controversial. The study was undertaken to asses the influence of acute hypothyroidism on left ventricular diastolic function and to elucidate possible underlying mechanisms by means of Doppler echocardiography in a group of athyreotic patients, whose thyroid state depended only on external thyroid hormone supply and could therefore easily be controlled. PATIENTS: Eleven patients (5 men, 6 women, aged 20-55 years), who had had total thyroidectomy, were investigated during mild hyperthyroidism and during acute hypothyroidism. Additionally, 11 healthy control subjects aged 25-51 years were included in the study. DESIGN: M-mode echocardiography of the left ventricle and pulsed-wave Doppler echocardiography of the transmitral flow velocity pattern were carried out. RESULTS: Acute hypothyroidism produced a decrease of left ventricular end-diastolic diameter from 48 +/- 5 to 46 +/- 5 mm (mean +/- SD P < 0.05), of peak velocity of early diastolic filling from 0.52 +/- 0.10 to 0.42 +/- 0.05 m/s (P < 0.05), of peak velocity of late diastolic filling from 0.42 +/- 0.10 to 0.36 +/- 0.09 m/s (P < 0.05), and a decreased time-velocity integral of early diastolic filling (6.2 +/- 1.8 vs 5.1 +/- 0.7 cm, P < 0.05). The other M-mode and Doppler echocardiographic parameters did not differ between the hyperthyroid and the hypothyroid states. CONCLUSIONS: The observed changes of the trans-mitral flow velocity pattern during acute hypothyroidism can be attributed to a reduction of pre-load. There is no direct evidence that acute hypothyroidism affects the intrinsic diastolic properties of the left ventricle.

Acute Disease↗