Peripartum cardiomyopathy.
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Cardiomyopathies↗
Biomedical subjects
S C Reimold
Publications and source records attributed to S C Reimold.
Propafenone for the treatment of supraventricular tachycardia and atrial fibrillation: a meta-analysis.
The purpose of this study was to determine propafenone's effectiveness in terminating and suppressing supraventricular arrhythmias using meta-analytic techniques. Published abstracts and manuscripts with these goals were selected and data abstracted on conversion and maintenance of sinus rhythm. Data were pooled using standard meta-analytic techniques and analyzed according to observation times, trial design (randomized versus nonrandomized), and route of drug administration. Propafenone successfully terminated 83.8% (95% confidence interval 78.1-89.7%) of supraventricular tachycardias. For supraventricular tachycardias, the proportion of patients remaining in sinus rhythm without recurrent arrhythmia was 64.6% (58.1-71.1%) at 1 year. The likelihood of converting a paroxysm of atrial fibrillation (AF) increased over time, with 76.1% (72.8-79.4%) of patients in sinus rhythm 24 hours after initiation of therapy. Patients receiving intravenous therapy were more likely to convert to sinus rhythm in the first 4 hours after drug administration. The treatment benefit of propafenone versus placebo in converting sinus rhythm was greatest in the first 8 hours after treatment (treatment benefit of 31.5% [24.5-38.5%] at 4 hours and 32.9% [24.3-41.5%] at 8 hours, p <0.01). This treatment benefit decreased to 1 1.0% (-0.6-22.4%) after 24 hours. Propafenone was effective in suppressing recurrences of AF in 55.4% (51.3-59.7%) at 6 months and 56.8% (52.3-61.3%) at 12 months. Thus, propafenone is effective in terminating supraventricular tachycardias and AF in the vast majority of patients. Suppression of arrhythmia recurrences is feasible in most patients, although its effectiveness decreases over time.
Anti-Arrhythmia Agents↗
Left ventricular pseudoaneurysm after epicardial patch electrode placement.
There are many known complications of implantable cardioverter-defibrillator placement. We treated a patient in whom a left ventricular pseudoaneurysm developed secondary to epicardial patch electrode placement and cardioverter-defibrillator implantation. The presenting symptoms, diagnostic evaluation, and surgical repair are described.
Aged↗
The mechanism of decrease in dynamic mitral regurgitation during heart failure treatment: importance of reduction in the regurgitant orifice size.
OBJECTIVES: The purpose of this study was to quantify and characterize the regurgitant flow pattern and regurgitant orifice area in patients undergoing therapy for severe heart failure using contemporary echocardiographic techniques. BACKGROUND: Mitral regurgitation may be dynamic in patients with heart failure and ultimately correlate with outcome in a group of patients. METHODS: Fourteen patients with severe heart failure felt to require hemodynamic monitoring for the optimization of medical therapy were enrolled. Two-dimensional and Doppler echocardiograms were performed before and following invasively guided therapy. Hemodynamics and standard echocardiographic dimensions were determined as well as regurgitant volume and regurgitant orifice area derived from color M-mode and Doppler measurements. RESULTS: Invasively guided therapy for heart failure was associated with a reduction in weight, filling pressures of the left and right heart, systemic vascular resistance, and echocardiographic left atrial, left ventricular and mitral annular dimensions. The mitral regurgitant volume decreased from 47+/-27 ml before therapy to 14+/-14 ml after therapy; p < 0.001. While therapy for heart failure markedly attenuated the volume of regurgitation, the pattern of regurgitant flow across the mitral valve was not significantly altered. In contrast, there was no difference in the velocity time integral of the continuous-wave Doppler spectra of mitral regurgitation with therapy (128+/-23 cm to 123+/-25 cm, p = 0.23). In all patients, the regurgitant orifice area decreased with therapy from 0.55+/-0.38 cm2 to 0.21+/-0.20 cm2 (p < 0.001). CONCLUSIONS: Pharmacologic reduction in filling pressure and systemic vascular resistance leads to a reduction in the dynamic mitral regurgitation of heart failure through a reduction in the regurgitant orifice area but not through a change in the gradient across the mitral valve. Reduction of the regurgitant orifice area is likely related to decreased left ventricular volumes and decreased annular distention.
Echocardiography, Doppler↗
Progressive enlargement of the regurgitant orifice in patients with chronic aortic regurgitation.
The severity of aortic regurgitation is dependent on the size of the regurgitant orifice, the left ventricular response to volume overload, and the diastolic pressure difference across the aortic valve. The purpose of this study was to test the hypothesis that the aortic regurgitant orifice increases over time in patients with audible chronic aortic regurgitation. To assess serial changes in aortic regurgitant severity by the use of two-dimensional and Doppler echocardiography, 59 patients (29 men and 30 women) with audible chronic aortic regurgitation were prospectively identified and evaluated annually with two-dimensional and Doppler echocardiograms. Patients were followed for a median of 38 months. We measured two separate indicators of the size of the regurgitant orifice: the color Doppler regurgitant jet width and the Doppler-derived regurgitant orifice area. Jet width increased with time (0.5 +/- 0.4 cm at baseline, 0.04 +/- 0.01 cm/year slope, p < 0.001). The regurgitant orifice area also increased (0.12 +/- 0.14 cm2 at baseline, 0.01 +/- 0.01 cm2/year, p = 0.05). Changes in regurgitant orifice area were related to changes in left ventricular end-diastolic dimension (p < 0.001). There were no significant changes in left ventricular chamber dimensions, volumes, and regurgitant volume over time in this cohort. Increases in jet width and orifice area occurred in patients with all degrees of baseline disease severity, with bicuspid or tricuspid leaflet morphology, and with male or female sex. In this prospective study of chronic aortic regurgitation, both jet width and Doppler-derived regurgitant orifice area increased over time. These findings suggest that one factor in the progression of chronic aortic regurgitation is enlargement of the orifice.
Aortic Valve↗
Gender-associated differences in left ventricular geometry in patients with aortic valve disease and effect of distinct overload subsets.
Gender-associated differences may play an important role in the way the left ventricle adapts to overload. The purpose of this study is to evaluate left ventricular (LV) geometry in patients referred for aortic valve replacement with distinct overload subsets. The echocardiograms of 128 patients with isolated aortic stenosis (n = 44), mixed aortic valvular disease (n = 51), and pure aortic regurgitation (n = 33) before aortic valve replacement were evaluated. Women had better LV function as measured by ejection fraction (58% vs 52%; p = 0.01) and were slightly older (67 vs 62 years, p = 0.11). LV dimensions and volumes indexes were distinctively smaller in women irrespective of the subgroups analyzed. Men had larger LV mass and LV mass index, but women had higher LV mass/volume ratio. Gender-related differences in LV mass/volume ratio were most prominent in the aortic stenosis patients (3.1 g/ml for women vs 2.3 g/ml for men; p = 0.001), tended to decrease in mixed aortic disease (2.3 g/ml for women vs 1.8 g/ml for men; p = 0.01), and were not present in patients with pure aortic regurgitation (1.7 g/ml for women vs 1.7 g/ml for men; p = 0.83). Multivariate analysis showed that gender was independently associated with LV mass/volume ratios, after adjusting for the severity of the valvular lesion, age, LV function, and concomitant coronary bypass graft surgery. Thus, in a selected population of patients with severe aortic valvular disease, there were significant gender-related differences in LV geometry, mainly in patients exposed to chronic pressure overload.
Aged↗
Risk of initiating antiarrhythmic drug therapy for atrial fibrillation in patients admitted to a university hospital.
BACKGROUND: The risks of antiarrhythmic therapy are increasingly recognized, but the risks associated with the initiation of antiarrhythmic therapy in patients hospitalized for atrial fibrillation are poorly defined. OBJECTIVE: To determine the incidence, time course, and predictors of adverse cardiac events that require intervention during initiation of antiarrhythmic drug therapy for atrial fibrillation. DESIGN: Retrospective chart review. SETTING: University hospital. PARTICIPANTS: 417 consecutive patients who underwent a total of 597 drug trials during a total of 550 hospitalizations for atrial fibrillation. INTERVENTION: Initiation of therapy with antiarrhythmic drugs: procainamide (189 trials), quinidine (179 trials), disopyramide (20 trials), propafenone (110 trials), flecainide (2 trials), sotalol (72 trials), and amiodarone (25 trials). Electrical conversion was performed during 247 trials. MEASUREMENTS: Incidence of adverse events and daily hazard rate were measured. Logistic regression was done to identify risk factors. RESULTS: During the 597 drug trials, 80 (13.4%) cardiac adverse events occurred in 73 patients. The risk was greatest during the first 24 hours of therapy. Bradyarrhythmias were the most common adverse event, occurring in 47 trials (7.9%); prolongation of the QT interval warranting discontinuation of drug therapy (9 trials; 1.5%) and ventricular arrhythmias (8 trials; 1.3%) were less frequent. In multivariate analysis, previous myocardial infarction was associated with increased risk (odds ratio, 1.90 [95% CI, 1.05 to 3.43]) and the association between older age and increased risk (odds ratio, 1.29 per decade [CI, 0.97 to 1.72]) was of borderline statistical significance. CONCLUSIONS: A significant risk for cardiac adverse events exists during initiation of antiarrhythmic therapy in patients hospitalized for atrial fibrillation. Observation with electrocardiographic monitoring seems advisable for 24 to 48 hours during initiation of antiarrhythmic therapy, particularly for elderly patients and patients who have previously had myocardial infarction.
Adult↗
Avoiding drug problems. The safety of drugs for supraventricular tachycardia.
To minimize drug problems in the treatment of supraventricular tachycardias, it is important to understand the spectrum of adverse events and to identify patients at high risk for these problems. Adverse cardiac and non-cardiac effects are associated, to varying degrees, with currently available antiarrhythmics. Cardiac adverse events include the development of rhythm disturbances, such as ventricular tachycardia or torsades des pointes, may result in syncope or death. In a meta-analysis of six randomized trials of quinidine vs placebo for atrial fibrillation, 1.8% of quinidine-treated patients died as opposed to 0.3% of placebo-treated patients. This increase in mortality was also noted in patients enrolled in the Stroke Prevention in Atrial Fibrillation Trial who were treated with type I antiarrhythmics. This increase in mortality was confined primarily to patients with a history of congestive heart failure. In a randomized trial of propafenone and sotalol for the treatment of atrial fibrillation, two out of 50 patients receiving sotalol died suddenly, one of whom had hypokalaemia-associated torsades des pointes. No patient receiving propafenone died during this trial. In a meta-analysis of propafenone's effect in treating supraventricular tachyarrhythmias in over 3100 adult patients, overall mortality was extremely low at 0.3%. Structural heart disease may increase the risk of antiarrhythmic agents. During inpatient drug trials in patients treated for atrial fibrillation at Brigham and Women's Hospital, adverse cardiac events, primarily bradyarrhythmias, occurred in up to 15% of the patients. Older age and prior myocardial infarction were associated with an increased risk of adverse events. Adverse drug problems may be minimized by careful attention to electrolytes, medications, concomitant medical illnesses, and underlying conduction disease. Careful monitoring of patients during initiation of therapy, especially those patients with ischaemic heart disease, congestive heart failure, and who are older, may minimize drug-related problems.
Adult↗
Echocardiographic predictors of survival after surgery for mitral regurgitation in the age of valve repair.
The objective of this study was to identify echocardiographic and clinical predictors of survival after mitral valve surgery when mitral repair is an option. In 132 patients undergoing mitral valve repair or replacement for the diagnosis of mitral regurgitation, preoperative echocardiograms were analyzed quantitatively and reviewed by two independent observers for structural abnormalities of the mitral valve. In Cox regression analysis, clinical factors such as age (mortality rate ratio [MRR] 1.7/decade, 95% confidence intervals [CI] 1.1, 2.4), and New York Heart Association class IV (MRR 3.1, 95% CI 1.4, 6.7) and echocardiographic factors including morphologic evidence of endocarditis or myxomatous disease (MRR 0.3, 95% CI 0.1, 0.7) were significant predictors of overall survival, although valve repair itself was not. End-systolic dimensions and volumes were not, likely related to the small number of patients with markedly increased end-systolic dimensions or volumes (5 patients [4%] with end-systolic dimension > 5.5 cm, 12 patients [9%] with end-systolic volume index > 60 ml/m2). New York Heart Association class IV (MRR 2.9, 95% CI 1.3, 6.4), age (MRR 1.7/decade, 95% CI 1.2, 2.6), and the presence of calcification (MRR 4.6, 95% CI 1.3, 16.2) were independent predictors of survival in multivariate analysis. In this contemporary cohort of patients undergoing repair or replacement for mitral regurgitation, factors such as echocardiographically determined cause of disease and presence of calcification predicted survival; traditional measurements such as end-systolic dimensions and volumes were less predictive, most likely because patients underwent surgery before their ventricles became markedly enlarged. Clinical factors such as age and functional status remained the most potent predictors of survival after surgery for mitral regurgitation.
Age Factors↗
Clinical challenge. I: Control of recurrent symptomatic atrial fibrillation.
Control of recurrent symptomatic atrial fibrillation should be directed at: (1) alleviation of symptoms associated with atrial fibrillation and (2) reduction of the risk of embolization. Approximately 50-60% of patients treated with conventional agents such as quinidine will develop recurrent atrial fibrillation in the first year of treatment. Because of this relapse rate and the side effects associated with quinidine and other type Ia antiarrhythmic agents, it is important to investigate the efficacy and safety of newer antiarrhythmic agents such as propafenone and sotalol. In our institution, 100 patients with recurrent symptomatic atrial fibrillation who had failed therapy with at least one type Ia agent were randomized to propafenone or sotalol. Propafenone and sotalol were equally effective in preventing recurrent atrial fibrillation at 6 and 12 months after onset of therapy independent of arrhythmia pattern or left atrial size. Both agents were well tolerated with only 10% of patients discontinuing therapy due to side effects. We combined data from this randomized study with a stepped care trial of propafenone and sotalol to examine risk factors for the development of recurrent atrial fibrillation. In patients treated with propafenone or sotalol, there was no significant difference in response to therapy based on age, gender, or aetiology of heart disease. Patients with dual-chamber pacing had improved maintenance of sinus rhythm as compared to those individuals without pacemakers. Left atrial size did not significantly influence the likelihood of maintaining sinus rhythm in these trials. Pharmacological management of the patient with recurrent symptomatic atrial fibrillation remains a difficult problem. Patient symptom severity and the clinical profile should be examined prior to instituting antiarrhythmic therapy in any given patient. These studies indicate that propafenone and sotalol are equally effective when used to maintain sinus rhythm in our population. As more data on the merits and risks of antiarrhythmic therapy for the treatment of atrial fibrillation become available, the role of propafenone and sotalol in the treatment of this disorder will be better understood.
Anti-Arrhythmia Agents↗
Catheter ablation of idiopathic left ventricular tachycardia associated with a false tendon.
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Adult↗
Risk factors for the development of recurrent atrial fibrillation: role of pacing and clinical variables.
Atrial fibrillation recurs in many patients treated with antiarrhythmic therapy to maintain sinus rhythm. From March 1985 to August 1991, 214 patients with recurrent symptomatic chronic or paroxysmal atrial fibrillation for which conventional antiarrhythmic agents had failed were treated with propafenone or sotalol. Baseline demographic data including the presence of pacing therapy were collected. Life-table estimates of the duration of freedom from atrial fibrillation were constructed on the basis of pacemaker status. Of 214 patients, 26 (12.1%) had pacing therapy. Patients with dual-chamber pacing were more likely to remain in sinus rhythm at 6 months (80%) than were patients with ventricular pacing (40%) or patients without pacing therapy (55%) (p = 0.002). A Cox univariate regression analysis demonstrated that dual-chamber pacing in contrast to ventricular pacing or no pacing was associated with a lower risk of recurrent atrial fibrillation. Clinical parameters such as age, gender, left atrial size, fibrillation pattern, drug assignment, ejection fraction, and underlying cardiac disease did not alter the risk of recurrent atrial fibrillation. Dual-chamber pacing was associated with a decreased likelihood of recurrent atrial fibrillation even after adjustment for other clinical covariates in a multivariate model (p = 0.04). In patients with recurrent atrial fibrillation treated with propafenone or sotalol, dual-chamber pacing improved maintenance of sinus rhythm.
Atrial Fibrillation↗
Preoperative prediction of prosthetic aortic valve annulus diameter by two-dimensional echocardiography.
Echocardiography may allow preoperative selection of appropriately sized aortic homograft valves. This study compared measurement of aortic annulus diameter from the preoperative transthoracic two-dimensional echocardiogram with prosthetic valve annulus diameter in 178 consecutive patients under-going primary aortic valve replacement. Aortic annulus diameter was measured independently from the two-dimensional parasternal long axis view by two experienced observers blinded to the size of valve implanted. Mean annulus diameter from three end-diastolic frames was recorded. Of the 178 patients, 124 (70%) of Observer 1 measurements and 102 (57%) of Observer 2 measurements were within 2mm of valve annulus diameter (p < 0.0001 for both observers). Six percent of Observer 1 measurements and 12% of Observer 2 measurements were more than 4mm away from valve annulus diameter. The echocardiographic prediction of valve size corresponded to actual prosthetic valve annulus diameter in 69 patients (39%) for Observer 1 and 60 patients (34%) for Observer 2. The percentages of echocardiographic measurements within two millimeter of valve annulus diameter were significantly different for the two observers (p < 0.05). The percentages of echocardiographic measurements within two millimeter of valve annulus diameter in 39 patients without significant aortic valve calcification were not significantly different from the remaining 139 patients with calcified valves. The interobserver coefficient of variation was 6.2% and the intraobserver coefficient of variation was 4.3%. Although preoperative measurement of aortic annulus diameter from transthoracic echocardiography approximates prosthetic valve annulus diameter in the majority of patients undergoing primary aortic valve replacement, a significant minority of estimates may be inaccurate, even in the absence of heavy calcification.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Recurrence of left atrial ball thrombus after surgical thrombectomy.
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Aged↗
Relationship of aortic regurgitant velocity slope and pressure half-time to severity of aortic regurgitation under changing haemodynamic conditions.
The slope and pressure half-time of the aortic regurgitant velocity spectrum have been used as non-invasive markers of regurgitant severity. Recent in vitro and theoretical work, however, has suggested a confounding effect of systemic vascular resistance and left ventricular compliance on these parameters. To study this situation in vivo, we have investigated the determinants of the aortic regurgitant velocity profile in an animal model of aortic regurgitation in which the regurgitation was induced surgically and in which the afterload was varied pharmacologically. Specifically, we examined the relationship of slope and pressure half-time of the aortic regurgitant velocity profile to the severity of aortic regurgitation under varying conditions of afterload using multilinear analysis. Slope varied directly with regurgitant orifice area and inversely with systemic vascular resistance and both left ventricular and aortic compliance (all P < 0.001). Pressure half-time related to these variables in the opposite direction. When the regurgitant orifice was variable in size, slope related directly (P < 0.001) and half-time inversely to the severity of the aortic regurgitation (the clinically expected response). In contrast, when the regurgitant orifice area was constant, slope varied inversely (P < 0.001) and half-time varied directly (P < 0.07) with the severity of the aortic regurgitation. Following nitroprusside infusion, slope tended to increase (P = 0.08) and pressure half-time tended to shorten (P = 0.08) despite a significant reduction in the regurgitant fraction (P = 0.009). Similarly, following dopamine infusion, a significant increase in regurgitant fraction (P = 0.01) was associated with a slight fall in aortic regurgitation slope and a lengthening of the half-time.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
An external aortic root device for decreasing aortic regurgitation: in vitro and in vivo animal studies.
OBJECTIVES: The purpose of this study was to determine if a device placed externally around the aortic root decreases regurgitant flow in acute aortic regurgitation. BACKGROUND: Aortic regurgitant flow is dependent on central aortic pressure and the aortic root and leaflet geometry. It may be possible to decrease aortic regurgitant severity by reducing aortic root size or dimension changes. METHODS: Aortic regurgitation was created in eight calf heart specimens suspended in a continuous flow system. Retrograde and antegrade aortic flow and distending aortic pressure were measured at baseline and after placement of an external aortic device at the level of the aortic annulus. In two additional specimens, the incompetent aortic valve was visualized fiberoptically before and after placement of the external device. Acute aortic regurgitation was created surgically in four live calves by excising a portion of the aortic leaflets. Antegrade and retrograde flow, left ventricular pressure, and central aortic pressure were measured at baseline, after creation of aortic regurgitation, and after placement of the external device. RESULTS: In the in vitro calf specimens, regurgitant flow decreased from 46.9 cc/sec to 15.1 cc/sec (66.0% +/- 21.8% decrease) after placement of the external device (p < 0.001). The regurgitant orifice area decreased from 0.13 +/- 0.04 cm2 to 0.04 +/- 0.02 cm2 after device placement (p < 0.001). Antegrade flow was reduced to a smaller extent (20.0% +/- 19.2% decrease) by the device (p < 0.05). Placement of the device around the aorta resulted in improved coaptation of the leaflets with a marked reduction in defect size by endoscopic visualization. Use of the external aortic device was associated with improvement in aortic regurgitant severity in three of four calves with surgically created aortic regurgitation. CONCLUSIONS: In these preliminary studies, acute experimental aortic regurgitant severity is decreased by the use of an external aortic device, probably due to reduction in aortic annular dimension changes and improved aortic leaflet apposition. Further studies are needed to determine the effectiveness of this device in chronic aortic regurgitation.
Animals↗
Dynamic nature of the aortic regurgitant orifice area during diastole in patients with chronic aortic regurgitation.
BACKGROUND: The effective aortic regurgitant orifice area varies with aortic pressure in animal models of acute aortic regurgitation. The purpose of this study was to determine whether the aortic regurgitant orifice area changes during diastole in patients with chronic aortic regurgitation. METHODS AND RESULTS: Two-dimensional and Doppler echocardiography were performed immediately before and after magnetic resonance velocity mapping using a cine phase contrast sequence in 17 patients with chronic aortic regurgitation. ECG-gated continuous-wave Doppler velocity time integrals and magnetic resonance flow rates were measured 16 times per cardiac cycle. The mean aortic regurgitant orifice area (centimeters squared) was calculated by the continuity equation. The regurgitant orifice area was also determined for each diastolic acquisition interval. Changes in the regurgitant orifice area during diastole were modeled using an asymptotic exponential decay model to determine the static and dynamic components of the orifice. The regurgitant orifice area increased directly with regurgitant fraction (y[cm2] = 0.0072[cm2/%]*x[%]-0.0409[cm2]; r = .86, P < .0001). In 15 of 17 (88%) patients, the regurgitant orifice area decreased during diastole. The dynamic component of the regurgitant orifice area decreased with increasing regurgitant fraction (y[%] = -0.98x[%]+96.9[%]; r = -.90, P < .0001). There were no significant differences in heart rate, systolic or diastolic blood pressures, or continuous-wave Doppler velocity time integrals measured before or after the magnetic resonance examination. CONCLUSIONS: The effective regurgitant orifice area decreases during diastole in patients with chronic aortic regurgitation. This phenomenon should be considered when evaluating aortic regurgitant severity.
Aortic Valve↗
Flow reversal in the descending aorta: a guide to intraoperative assessment of aortic regurgitation with transesophageal echocardiography.
This study assessed the value of biplane transesophageal echocardiographic assessment of diastolic flow reversal in the descending aorta as an alternative to Doppler color flow imaging in determining severity of aortic regurgitation. In 45 patients undergoing cardiac operations, the severity of aortic regurgitation was assessed by semiquantitative grading of the width of the Doppler color flow regurgitant jet relative to the left ventricular outflow tract, and the presence of diastolic flow reversal was assessed with pulsed-wave Doppler measurements at three sites in the descending aorta. In four patients, the diastolic flow reversal method was the only available form of assessment because of inadequate visualization of the left ventricular outflow tract beneath a mitral valve prosthesis. Diastolic flow reversal in the descending aorta was not observed in patients without aortic regurgitation and was always present in patients with severe aortic regurgitation. Aortic valve replacement successfully eliminated descending aortic flow reversal in all 19 patients in whom it was present before valve replacement. Identification of diastolic flow reversal at multiple sites in the descending aorta with biplane transesophageal echocardiography helps to confirm the presence of severe aortic regurgitation and can serve as an alternative method of assessment when visualization of the left ventricular outflow tract is impaired.
Aged↗