Mechanics of pulsus alternans in aortic valve stenosis.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 62-year-old patient underwent catheter balloon valvuloplasty for aortic valve stenosis. During the procedure, iatrogenic severe mitral regurgitation was induced, requiring emergency surgery. At operation, extensive laceration of the septal mitral leaflet was found; chordae tendinae were intact. Retrospective examination of the cineangiogram revealed the presence of balloon indentation at the chordal level during inflation, which disappeared at full inflation. Mitral valve rupture was probably related to balloon entrapment in chordae tendinae, severe chordal stretching at inflation, and subsequent valve laceration. This severe complication or aortic valvuloplasty in adults has not been reported previously and probably could be avoided by careful observation of guidewire and balloon position before inflation.
BACKGROUND: Diastolic dysfunction with delayed relaxation and abnormal passive elastic properties has been described in patients with severe pressure overload hypertrophy. The purpose of this study was to evaluate the time course of rotational motion of the left ventricle in patients with aortic valve stenosis using myocardial tagging. METHODS: Myocardial tagging is a non-invasive method based on magnetic resonance which makes it possible to label ('tag') specific myocardial regions. From the motion of the tag's cardiac rotation, radial displacement and translational motion can be determined. In 12 controls and 13 patients with severe aortic valve stenosis systolic and diastolic wall motion was assessed in an apical and basal short axis plane. RESULTS: The normal left ventricle performs a systolic wringing motion around the ventricular long axis with clockwise rotation at the base (-4.4+/-1.6 degrees) and counter-clockwise rotation at the apex (+6.8+/-2.5 degrees) when viewed from the apex. During early diastole an untwisting motion can be observed which precedes diastolic filling. In patients with aortic valve stenosis systolic rotation is reduced at the base (-2.4+/-2.0 degrees; P<0.01) but increased at the apex (+12.0+/-6.0 degrees; P<0.05). Diastolic untwisting is delayed and prolonged with a decrease in normalized rotation velocity (-6.9+/-1.1 s(-1)) when compared to controls (-10.7+/-2.2 s(-1); P<0.001). Maximal systolic torsion is 8.0+/-2.1 degrees in controls and 14.1+/-6.4 degrees (P<0.01) in patients with aortic valve stenosis. CONCLUSIONS: Left ventricular pressure overload hypertrophy is associated with a reduction in basal and an increase in apical rotation resulting in increased torsion of the ventricle. Diastolic untwisting is delayed and prolonged. This may explain the occurrence of diastolic dysfunction in patients with severe pressure overload hypertrophy.
Impaired reflex control of heart rate seems to be associated with increased risk of sudden cardiac death. To assess the effect of aortic valve stenosis on parasympathetic heart rate control we measured the heart rate responses to deep breathing and to standing up, non-invasive measures of cardiac parasympathetic activity, in 24 patients with valvular aortic stenosis and in 24 healthy asymptomatic subjects of the same age group. All but one of the patients were symptomatic and the mean aortic valve pressure gradients ranged from 32 to 114 mmHg. The heart rate response to deep breathing was significantly (P less than 0.05) lower in valve patients than in the healthy subjects. The heart rate changes evoked by standing up, however, did not differ significantly between the groups. The heart rate response to deep breathing was inversely weakly related to the left ventricular end-diastolic pressure (r = -0.41, P less than 0.05), but not significantly to the aortic valve pressure gradient, valve area, left ventricular ejection fraction or presence of coronary artery disease. Our results suggest that the impairment of reflex heart rate control is common in patients with significant aortic valve stenosis.
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We compared two different magnetic resonance (MR) sequences [steady-state free precession (SSFP) and gradient echo fast low-angle shot (FLASH)] for the assessment of aortic valve areas in aortic stenosis using transesophageal echocardiography (TEE) as the standard of reference. Thirty-two patients with known aortic stenosis underwent MR (1.5 T) using a cine SSFP sequence and a cine FLASH sequence. Planimetry was performed in cross-sectional images and compared to the results of the TEE. In seven patients the grade of stenosis was additionally assessed by invasive cardiac catheterization (ICC). The mean aortic valve area measured by TEE was 0.97+/-0.19 mm(2), 1.00+/-0.25 mm(2) for SSFP and 1.25+/-0.23 mm(2) based on FLASH images. The mean difference between the valve areas assessed based on SSFP and TEE images was 0.15+/-0.13 cm(2) (FLASH vs TEE: 0.29+/-0.17 cm(2)). Bland-Altman analysis demonstrated that measurements using FLASH images overestimated the aortic valve area compared to TEE. Comparing ICC with MRI and TEE, only a weak to moderate correlation was found (ICC vs TEE: R=0.52, p=0.22; ICC vs SSFP: R=0.20, p=0.65; ICC vs FLASH: R=0.16, p=0.70). Measurements of the aortic valve area based on SSFP images correlate better with TEE compared to FLASH images.
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Assessing the severity of aortic stenosis remains an important clinical problem. The turbulent pressure fluctuations generated by the jet downstream of the stenotic valve produce vibrations in the aortic wall. These vibrations are transmitted through the chest to the skin surface, where they can be recorded as systolic ejection murmurs. The purpose of the present study was to estimate the transvalvular aortic pressure difference by spectral analysis of heart murmurs (spectral vibrocardiography). Forty-four patients with clinical signs of aortic stenosis underwent cardiac catheterization to measure the transvalvular pressure difference. In a double blind prospective study, precordial vibrations were measured prior to catheterization using a dedicated heart sound analyzer (Vibrocard 2000) to calculate the spectral ratio of murmur energy between 100-500 Hz and 20-500 Hz. Three different weighting filters were used to compensate for individual differences in the transthoracic attenuation of murmurs. The square root of the murmur energy ratio correlated linearly with the mean transvalvular pressure difference (r = 0.80, SEE = 13 mmHg) and with the peak transvalvular pressure difference (r = 0.81, SEE = 16 mmHg). The use of individual compensation filters improved the correlation. This study shows that it is possible to estimate the transvalvular pressure difference in patients with aortic valve stenosis by spectral analysis of heart murmurs. It is a fast, simple and cost effective technique, which requires less skill than conventional methods.
Percutaneous balloon valvotomy was performed in 21 cases (aged 6 to 62 years) with moderate to severe aortic valve stenosis, using either single (16 cases) or double balloon (5 cases) technique. All patients had basal transaortic pressure gradient 50 mmHG or above. A majority of patients had significant haemodynamic improvement immediately following balloon dilatation. The mean systolic transaortic pressure gradient reduced from 94 mmHg (range 50 to 160) to 42 mmHg (range 14 to 82; P less than 0.05) immediately after the dilatation. The final gradient was less than 40 mmHg in 11 cases. The mean cardiac index improved from 3.86 L/min/M2 (range 2.8 to 5.2) to 4.14 L/min/M2 (range 3.4 to 5.6; P:NS) following the procedure. There was no death or major complication related to the intervention. There was a procedure-related mild aortic regurgitation in 4 cases. We conclude that percutaneous balloon dilatation is an effective, safe, low cost, nonsurgical method for treating patients with aortic valve stenosis.
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PURPOSE: to evaluate the exercise test as a prognostic factor for asymptomatic patients with aortic valve stenosis. METHODS: During 60 months 70 patients with aortic valve area < or = 1 cm2 without any other heart lesion were studied. The patients underwent Dopplerechocardiograms exercise tests (considered positive in the presence of electrocardiographic changes or symptoms) and clinical follow-up in order to determine the onset of symptoms or sudden death. RESULTS: The event-free probability was 50% after 16 months of follow-up. There was no relationship between the occurrence of events and the sex or to the transvalvar gradient. However, there was a statistically significant association between the incidence of events (p = 0.0124), valvar area (p = 0.0003) and exercise test results (p = 0.0001). CONCLUSION: Patients with significant aortic stenosis even without symptoms, have a low survival rate and the exercise test is a good prognostic factor during follow-up.
A 67-year-old man was referred for evaluation of near-syncopal attacks and left hemiparesis. Echocardiography revealed moderate to severe calcific aortic valve stenosis and a free-floating thrombus. Left ventricular (LV) systolic function was normal. No regional wall motion abnormality was detected in the left ventricle. On serial echocardiography, the thrombus began to fragment. Urgent surgery was commenced, during which the mass was seen to be a free-floating ball thrombus in the LV cavity, in addition to apical fibrin bands mimicking abnormal trabeculation. The thrombus was removed and aortic prosthetic valve replacement performed. No coagulation abnormalities were detected. The patient made a full recovery after surgery. Floating thrombus can embolize at any moment and require emergency treatment, notably because of a high mortality rate of systemic embolic events or acute hemodynamic decompensation caused by LV outflow tract obstruction. To the authors' knowledge, this is the first report of LV free-floating thrombus concomitant with isolated calcific aortic valve stenosis.