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H P Hamer

Publications and source records attributed to H P Hamer.

14 recordsLinked to original sources
PubMed1996

Usefulness of multiplane transesophageal echocardiography to improve the assessment of severity of mitral regurgitation.

This study was designed to examine the accuracy of multiplane transesophageal echocardiography (TEE) color Doppler measurements in comparison to monoplane or biplane measurements in estimating the severity of mitral regurgitation (MR). Multiplane TEE potentially increases diagnostic accuracy of transesophageal examinations; it is unknown if multiplane is more accurate in assessing the severity of MR than monoplane or biplane TEE. Left ventricular cineangiograms of 91 patients with MR (40 no or mild, 30 moderate, and 21 severe) were compared with systolic pulmonary venous flow reversal and transesophageal color Doppler measurements: jet area and length in the transverse and longitudinal plane, maximal and average of those 2 planes (biplane), and maximal and average of 11 different planes (multiplane). Flow reversal (16 patients) identified severe MR with a specificity of 96% and a sensitivity of 62%; these were 96% and only 10% to 43%, respectively, for color Doppler measurements. In the absence of flow reversal, multiplane maximal jet area predicted severe MR with a sensitivity of 88% and a specificity of 75%, which were 85% and 76%, respectively, for no or mild MR; this did not differ significantly from results obtained by monoplane or biplane measurements. Color Doppler measurements of eccentric jets were not reliable for identification of severe MR. Systolic pulmonary venous flow reversal identifies 2 of 3 patients with severe MR with a high accuracy. In patients without flow reversal, multiplane color Doppler TEE is very capable of assessing MR severity, but biplane and monoplane TEE are equally accurate.

Adult↗
PubMed1996

Value of systolic pulmonary venous flow reversal and color Doppler jet measurements assessed with transesophageal echocardiography in recognizing severe pure mitral regurgitation.

We evaluated the value of color and pulsed Doppler transesophageal echocardiographic parameters and of V waves in estimating the severity of mitral regurgitation (MR) in 62 consecutive patients (38 men and 24 women, aged 39 to 80 years) with angiographically proven chronic pure MR (15 grade I/II, 47 grade III/IV). Twenty patients were examined before cardiac surgery under general anesthesia. Sensitivity, specificity, and positive and negative predictive values of systolic pulmonary venous flow reversal for the presence of grade III/IV MR were 87%, 93%, 98%, and 64%, respectively, these were for jet areas > or = 8.0 cm2--66%, 100%, 100%, and 48%, for jet lengths > or = 50 mm--70%, 87%, 94%, and 48%, for enlarged V waves--86%, 38%, 83%, and 43%, and for either flow reversal or a jet area > or = 8.0 cm2--96%, 93%, 98%, and 88%. We conclude that a combination of measurements improved the negative predictive value considerably, which is of importance in a population with a high pretest probability of severe MR. Enlarged V waves are not reliable in predicting severe MR. The optimal cutoff value for jet area and jet length was lower in anesthesized patients than in conscious patients; in anesthesized patients, sensitivity, specificity, and positive and negative predictive values of jet area > or = 5.0 CM2 for grade III/IV MR were 67%, 100%, 100%, and 50%, respectively; these were 87%, 100%, 100%, and 71% for flow reversal. Because the results of mitral repair are often evaluated with transesophageal echocardiography during surgery, our findings have clinical implications for evaluation of severe MR in anesthesized patients: pulmonary venous flow direction is the first-choice measure; jet area can be used when a low cutoff point is chosen.

Adult↗
PubMed1996

Assessment of quantitative hypertrophy scores in hypertrophic cardiomyopathy: magnetic resonance imaging versus echocardiography.

To compare the diagnostic value of spin-echo magnetic resonance (MR) imaging and transthoracic echocardiography in quantitative assessment of the extent of hypertrophy in patients with hypertrophic cardiomyopathy (HCM), we examined 52 consecutive patients with HCM. The Spirito-Maron and Wigle hypertrophy scores were calculated with wall thickness measurements obtained by both imaging modalities. MR imaging yielded complete assessment of anatomic features and allowed calculation of hypertrophy scores in 49 patients (94%). Adequate echocardiograms were obtained in 33 patients (63%) and correlated well with MR imaging for wall thickness measurements and for determination of the two hypertrophy scores (both r> 0.9). MR imaging provided additional information not available by echocardiography in 16 patients (31%). We conclude that the Spirito-Maron and Wigle hypertrophy scores correlated well between echocardiography and MR imaging. Because echocardiography was of insufficient quality for calculating adequate hypertrophy scores in 19 (37%) patients, MR imaging provided the most comprehensive diagnostic information in patients with HCM.

Adult↗
PubMed1996

Biplane transesophageal color-flow Doppler imaging in assessing severity of mitral regurgitation: influence of hemodynamic circumstances and mechanism of regurgitation.

OBJECTIVE: To determine the value of biplane transesophageal echocardiography in the assessment of severity of mitral regurgitation compared with left ventricular angiography. DESIGN: Prospective study of consecutive patients. SETTING: Two university hospitals, one community hospital. PARTICIPANTS: Thirty-seven patients with angiographically proven mitral regurgitation. INTERVENTION: Transthoracic and biplane transesophageal echocardiography. In 19 patients, transesophageal echocardiography was performed during general anesthesia. MEASUREMENTS AND MAIN RESULTS: The largest mitral regurgitation jet area and longest jet as obtained with Doppler color-flow mapping from transthoracic and biplane transesophageal echocardiography and pulsed-Doppler pulmonary venous flow characteristics. Sensitivity and 100-minus-specificity were plotted to constitute receiver operating characteristics (ROC) curves. Areas under ROC curve for transverse, longitudinal, and biplane jet area were 0.77, 0.75, and 0.81, and for jet length, 0.82, 0.84, and 0.88, respectively; this was for biplane jet area in conscious patients; 0.99 compared with 0.72 in anesthetized patients (p < 0.05). CONCLUSIONS: Biplane measurements identified severe mitral regurgitation slightly more reliably than the transverse or longitudinal measurements alone. In conscious patients, jet area was an excellent test for estimating severity of mitral regurgitation. In anesthetized patients, a combination of biplane jet area and length and of systolic pulmonary venous flow reversal accurately predicted angiographic severity of mitral regurgitation. In anesthetized patients, the optimal cut-off value for jet area to distinguish between moderate and severe mitral regurgitation was lower than in conscious patients. In the total population, regardless of hemodynamic and technical variations, a combination of biplane jet area and length and of systolic pulmonary venous flow reversal accurately predicted the severity of mitral regurgitation.

Adult↗
PubMed1995

Additional value of biplane transesophageal echocardiography in assessing the genesis of mitral regurgitation and the feasibility of valve repair.

To determine the additional diagnostic value of biplane transesophageal echocardiography (TEE) in patients undergoing mitral valve surgery, we studied 48 patients with severe mitral regurgitation. Transesophageal echocardiographic video recordings were reorganized in separate transverse and longitudinal sections to allow independent evaluation. Mechanism of mitral regurgitation and anatomic abnormalities of the mitral valve were assessed by all 3 transesophageal echocardiographic modalities and were related to surgical findings. Biplane TEE detected increased leaflet mobility with a sensitivity of 91% and a specificity of 84%, and restricted leaflet mobility with a sensitivity of 100% and a specificity of 97%. Biplane TEE was accurate in the diagnosis of most of the anatomic abnormalities associated with these mechanisms. However, the sensitivity for detecting subvalvular abnormalities (including papillary muscle abnormalities) was poor, and measurement of the annular diameter had a poor correlation with annular dilatation. Although the yield of biplane TEE was better than either transverse or longitudinal TEE alone, the differences did not reach statistical significance, because of the size of the patient group. The surgical procedure (either valve repair or replacement) was correctly predicted with transverse TEE in 71%, with longitudinal TEE in 69%, and with biplane TEE in 79% of the patients. All 3 transesophageal echocardiographic modalities are very capable of assessing the anatomic abnormalities and mechanism of mitral regurgitation, as well as predicting the feasibility of valve repair.

Aged↗
PubMed1995

Comparative effects of diltiazem and lisinopril on left ventricular structure and filling in mild-to-moderate hypertension.

The comparative effects on echocardiographically determined left ventricular (LV) mass and pulsed Doppler derived indexes of LV diastolic filling were studied in previously untreated hypertensive patients after 6 months of treatment with diltiazem 300 mg once daily (o.d.) (n = 16), and lisinopril 20 mg o.d. (n = 20). LV mass index decreased in the lisinopril group (from 98 to 96 g/m2; mean difference after 6 months of treatment with diltiazem-lisinopril was 13.7 g/m2 [95% confidence interval (CI) 0.8 to 26.6, p < 0.05]. In both groups diastolic filling parameters improved, but there was no statistically significant difference between the groups. Both treatment regimens showed a similar decrease in office and maximal exercise systolic blood pressure (SPB). Ambulatory daytime BP was lower after lisinopril treatment (from 147/96 to 126/83 mm Hg) than after diltiazem treatment (from 142/93 to 135/87 mm Hg); mean difference between diltiazem and lisinopril after 6 months of treatment was 9.7 (95% CI 3.4 to 16.0, p < 0.05)/9.4 (95% CI 2.5 to 16.3, p < 0.05) mm Hg. Nighttime BP decreased from 129/81 to 113/70 mm Hg in the lisinopril group, but not in the diltiazem group (from 125/79 to 122/77 mm Hg); mean difference between diltiazem and lisinopril after 6 months of treatment was 4.4 (95% CI - 0.2 to 8.9)/6.6 (95% CI 1.1 to 12.0) mm Hg. Changes in diastolic filling parameters were significantly correlated with changes in LV mass index in the lisinopril group, suggesting that the improvements in diastolic filling in the diltazem group may be partly due to an effect on factors other than LV mass.

Adult↗
PubMed1995

Increased dispersion of refractoriness in the absence of QT prolongation in patients with mitral valve prolapse and ventricular arrhythmias.

BACKGROUND: The mechanism responsible for the reported high incidence of ventricular arrhythmias in mitral valve prolapse is not clear. Electrocardiographic studies show an increased occurrence of repolarisation abnormalities on the 12 lead surface electrocardiogram, indicating regional differences in ventricular recovery. The purpose of this study was to investigate whether dispersion of refractoriness was an arrhythmogenic mechanism. METHODS: QT dispersion was measured in 32 patients with echocardiographically documented mitral valve prolapse and ventricular arrhythmias on 24 hour Holter recordings. QT dispersion was defined as the difference between the maximum and minimum average QT interval in any of the 12 leads of the surface electrocardiogram. QT dispersion corrected for heart rate was calculated by Bazett's formula. The results were compared with the data from 32 matched controls without a history of cardiac disease. Patients taking drugs that influence the QT interval and patients with a QRS duration > 120 ms were excluded. RESULTS: QT dispersion was greater in patients with mitral valve prolapse than in matched controls (60 (20) v 39 (11 ms) respectively, P < or = 0.001) as was corrected QT (64 (20 ms) v 43 (12 ms) respectively, P < or = 0.001). There was no significant difference in minimum or maximum QT intervals between the two groups. CONCLUSIONS: QT dispersion on the 12 lead surface electrocardiogram was greater in patients with mitral valve prolapse with ventricular arrhythmias than in normal controls, but the maximum QT interval was not increased. The results accord with the hypothesis that regional shortening and lengthening of repolarisation times in patients with mitral valve prolapse may account for the increased dispersion of refractoriness.

Arrhythmias, Cardiac↗
PubMed1993

Changes in left and right atrial size after cardioversion of atrial fibrillation: role of mitral valve disease.

OBJECTIVES: The aim of this study was to examine the effect of cardioversion on left and right atrial volume in patients with chronic atrial fibrillation and to determine the influence of mitral valve disease on atrial size. BACKGROUND: Atrial enlargement is a common finding in atrial fibrillation and has been associated with an increased risk for embolic stroke. In addition, atrial enlargement may hamper long-term maintenance of sinus rhythm after cardioversion. METHODS: Forty-one patients with chronic atrial fibrillation (mean duration +/- SD, 45 +/- 62 months) underwent two-dimensional echocardiography before and 6 months after cardioversion to determine left and right atrial dimensions. Underlying heart disease was present in 26 patients: mitral valve disease in 12 (stenosis in 5, regurgitation in 5 and a combination in 2 patients) and other heart diseases in 14. Fifteen patients had lone atrial fibrillation. Patients with sustained sinus rhythm were compared with those who had a relapse of the arrhythmia 6 months after cardioversion. RESULTS: Six months after cardioversion, 28 patients still had sinus rhythm, whereas 13 patients had a relapse of the arrhythmia. In the 28 patients who had sinus rhythm after 6 months, left and right atrial volume decreased from a mean (+/- SD) 72.6 +/- 15.1 to 58.5 +/- 13.8 cm3 (-20%, p < 0.05) and from 68.7 +/- 14.6 to 58.6 +/- 11.6 cm3 (-14%, p < 0.05), respectively. Atrial dimensions also decreased significantly in the subgroup of patients with mitral valve disease. In contrast, no change in atrial size occurred in the 13 patients who had a relapse of atrial fibrillation. Left ventricular function did not change between the two echocardiographic studies, although New York Heart Association class improved in patients who had sinus rhythm after 6 months. CONCLUSIONS: Restoration of sinus rhythm reverts the process of left and right atrial enlargement in patients with chronic atrial fibrillation and mitral valve disease. Therefore, cardioversion may reduce the incidence of thromboembolic complications and prevent the arrhythmia from becoming refractory to medical therapy.

Aged↗
PubMed1989

Efficacy and safety of flecainide acetate in the maintenance of sinus rhythm after electrical cardioversion of chronic atrial fibrillation or atrial flutter.

The efficacy and safety of flecainide were studied in the maintenance of sinus rhythm after electrical cardioversion for chronic atrial fibrillation or atrial flutter. Eighty-one patients were randomized to flecainide treatment or no treatment. Baseline characteristics of both groups were comparable. Compared to previous studies, patients could be classified as difficult-to-treat patients. Multiple regression analysis showed New York Heart Association class I for exercise tolerance (p = 0.0004) and flecainide treatment (p = 0.01) to be the main factors increasing the arrhythmia-free episode. However, Mantel-Cox lifetable analysis did not reveal significant differences between arrhythmia-free survival curves of both treatment groups. In the flecainide-treated group, 9% of patients experienced side effects, mostly related to negative dromotropic effects. The incidence of ventricular proarrhythmia in this group of patients was low. Thus, flecainide may be effective in postponing arrhythmia recurrence, even in difficult-to-treat patients. Caution should be excercised in treating patients with underlying conduction disturbances, sick sinus syndrome or characteristics favoring development of ventricular proarrhythmia.

Adolescent↗