Seward, James B.

BackgroundIn patients with mitral valve prolapse, spontaneous changes of the effective regurgitant orifice during systole are not well documented. Such changes can now be analyzed by use of the proximal isovelocity surface area method, but the changes raise concern about the reliability of this method for assessing overall severity of regurgitation in these patients.Methods and ResultsIn a prospective study of 42 patients with mitral valve prolapse, the effective mitral regurgitant orifice was calculated at four phases of systole (early, mid, mid-late, and late) as the ratio of regurgitant flow to regurgitant velocity by use of the proximal isovelocity surface area method. Throughout systole, the effective regurgitant orifice increased significantly, from 32±27 mm2in early systole to 41±27 in midsystole, 55±30 in mid-late systole, and 107±66 mm2during late systole (P<.0001). Phasic regurgitant volume increased from early to mid-late systole but decreased in late systole. For quantitation of the overall effective regurgitant orifice, four approaches using the proximal isovelocity surface area were compared with simultaneously performed quantitative Doppler echocardiography (54±30 mm2) and quantitative two-dimensional echocardiography (51±29 mm2). All correlations were good (r>.95), but overestimation was considerable when the largest flow convergence was used (70±39 mm2; bothP<.0001), significant when the simple mean of the four phases was used (59±36 mm2;P=.005 andP=.0007, respectively), mild when a weighted mean of the four phases was used (55±33 mm2;P=.41 andP=.01, respectively), and no overestimation was observed when the effective regurgitant orifice calculated at maximum regurgitant velocity was used (54±30 mm2;P=.29 andP=.17, respectively).ConclusionsPhasic changes of mitral regurgitation are observed in patients with mitral valve prolapse. The effective regurgitant orifice increases throughout systole. Regurgitant volume also increases initially but tends to decrease in late systole. These changes can lead to overestimation of the overall degree of regurgitation, but properly timed measurements made by use of the proximal isovelocity surface area method allow an accurate estimation of the overall effective regurgitant orifice.

Background —The outcome of aortic regurgitation conservatively followed in clinical practice is poorly defined. Methods and Results —Long-term outcome of 246 patients with severe or moderately severe aortic regurgitation diagnosed by color Doppler echocardiography was analyzed. With conservative management, mortality rate was higher than expected (at 10 years, 34±5%, P <0.001) and morbidity was high (10-year rates of 47±6% for heart failure and 62±4% for aortic valve surgery). At 10 years, 75±3% of patients had died or had surgery and 83±3% had had cardiovascular events. In multivariate analysis, predictors of survival were age ( P <0.001), functional class ( P <0.001), comorbidity index ( P =0.033), atrial fibrillation ( P =0.002), and left ventricular end-systolic diameter corrected for body surface area ( P =0.025). Ejection fraction was also an independent predictor of overall survival, including postoperative follow-up of surgically treated patients ( P <0.001). High risk during conservative treatment, with mortality rate in excess of that expected, was noted among patients with severe, even transient, symptoms (24.6% yearly, P <0.001) but also in those with mild (class II) symptoms (6.3% yearly, P =0.02) and in asymptomatic patients with left ventricular ejection fraction <55% (5.8% yearly, P =0.03) or with end-systolic diameter normalized to body surface area ≥25 mm/m 2 (7.8% yearly, P =0.004). Surgery performed during follow-up was independently associated with reduced cardiovascular mortality (adjusted hazard ratio, 0.54; P =0.048). Conclusions —Patients diagnosed with severe aortic regurgitation in clinical practice incur excess mortality and high morbidity, underscoring the serious prognosis of the disease. Surgery, which reduces cardiac mortality rates, should be considered promptly in high-risk patients.

Background —Idiopathic restrictive cardiomyopathy is a poorly recognized entity of unknown cause characterized by nondilated, nonhypertrophied ventricles with diastolic dysfunction resulting in dilated atria and variable systolic function. Methods and Results —Between 1979 and 1996, 94 patients (61% women) 10 to 90 years old (mean, 64 years) met strict morphological echocardiographic criteria for idiopathic restrictive cardiomyopathy, mainly dilated atria with nonhypertrophied, nondilated ventricles. None had known infiltrative disease, hypertension of >5 years’ duration, or cardiac or systemic conditions associated with restrictive filling. Nineteen percent were in NYHA class I, 53% in class II, and 28% in class III or IV. Atrial fibrillation was noted in 74% of patients and systolic dysfunction in 16%. Follow-up (mean, 68 months) was complete for 93 patients (99%). At follow-up, 47 patients (50%) had died, 32 (68%) of cardiovascular causes. Four had heart transplantation. The death rate compared with actuarial statistics was significantly higher than expected ( P <0.0001). Kaplan-Meier 5-year survival was 64%, compared with expected survival of 85%. Multivariate analysis using proportional hazards showed that the risk of death approximately doubles with male sex (hazard ratio [HR] =2.1), left atrial dimension >60 mm (HR=2.3), age >70 years (HR=2.0), and each increment of NYHA class (HR=2.0). Conclusions —Idiopathic restrictive cardiomyopathy or nondilated, nonhypertrophic ventricles with marked biatrial dilatation, as defined morphologically by echocardiography, affects predominantly elderly patients but can occur in any age group. Patients present with systemic and pulmonary venous congestion and atrial fibrillation and have a poor prognosis, particularly men >70 years old with higher NYHA class and left atrial dimension >60 mm.

Background —The clinical spectrum of constrictive pericarditis (CP) has been affected by a change in incidence of etiological factors. We sought to determine the impact of these changes on the outcome of pericardiectomy. Methods and Results —The contemporary spectrum of CP in 135 patients (76% male) evaluated at the Mayo Clinic from 1985 to 1995 was compared with that of a historic cohort. Notable trends were an increasing frequency of CP due to cardiac surgery and mediastinal radiation and presentation in older patients (median age, 61 versus 45 years). Perioperative mortality decreased (6% versus 14%, P =0.011), but late survival was inferior to that of an age- and sex-matched US population (57±8% at 10 years). The long-term outcome was predicted independently by 3 variables in stepwise logistic regression analyses: (1) age, (2) NYHA class, and most powerfully, (3) a postradiation cause. Of 90 late survivors in whom functional class could be determined, functional status had improved markedly (2.6±0.7 at baseline versus 1.5±0.8 at latest follow-up [ P <0.0001]), with 83% being free of clinical symptoms. Conclusions —The evolving profile of CP, with increasingly older patients and those with radiation-induced disease in the past decade, significantly affects postoperative prognosis. Long-term results of pericardiectomy are disappointing for some patient groups, especially those with radiation-induced CP. By contrast, surgery alleviates or improves symptoms in the majority of late survivors.

Background Respiratory variation of ≥25% in mitral E velocity is a characteristic Doppler echocardiographic feature in constrictive pericarditis. However, a subset of patients with constriction do not exhibit the typical respiratory change, most likely because of marked increase in the left atrial pressure, and preload reduction may unmask the respiratory variation. Methods and Results In 12 patients with surgically confirmed constrictive pericarditis who had <25% respiratory variation in mitral E velocity during an initial preoperative examination, the Doppler study was repeated after an attempt to decrease left ventricular filling pressure. At baseline, mean mitral E velocity was similar after inspiration and expiration (0.81±0.24 and 0.84±0.21 m/s, respectively). On repeat Doppler examination, with the patient in a head-up tilt or sitting position, the decrease in mitral E velocity with inspiration (0.61±0.13 m/s) was significant ( P <.004), whereas it did not change significantly with expiration. The mean percent respiratory change in E velocity was 5±7% at baseline and 32±28% with preload reduction. Eight (75%) of the 12 patients developed respiratory variation of ≥25%. Conclusions When the respiratory variation in Doppler mitral E velocity is blunted or absent during the evaluation of suspected constrictive pericarditis, repeat Doppler recording of mitral flow velocities after maneuvers to decrease preload is recommended to unmask the characteristic respiratory variation in mitral E velocity.

Patients with hypertension exhibit impaired energetic coupling between the ventricle and the arterial system, leading to reduced cardiac mechanic efficiency and exercise capacity. We tested whether blood pressure normalization with current antihypertensive therapy can improve arterioventricular coupling. Eighteen hypertensive patients without other cardiovascular disease were examined before and after antihypertensive therapy. Transthoracic echocardiography was performed. Central aortic pressure waveforms, including end-systolic pressure, were derived from radial artery applanation tonometry. Afterload was increased with isometric handgrip exercise. Central aortic end-systolic pressure and ventricular volumes at rest and handgrip were used to calculate ventricular elastance, effective arterial elastance, arterioventricular coupling (effective arterial elastance/ventricular elastance), and mechanical efficiency. After 142±67 days, systolic blood pressure decreased from 150.9±14.6 to 119.8±9.2 mm Hg ( P <0.00001), diastolic blood pressure from 85.9±14.8 to 68.8±8.4 mm Hg ( P =0.00002), and cardiac output from 5.8±1.7 to 4.9±1.8 L/min ( P =0.03). Resting left ventricular end-systolic volume, ejection fraction, and septal thickness did not change. Ventricular elastance increased from 1.7±1.0 to 3.2±1.4 mm Hg/mL ( P =0.00002), whereas effective arterial elastance decreased from 1.4±0.5 to 1.2±0.4 mm Hg/mL ( P =0.02). Effective arterial elastance/ventricular elastance decreased in all patients, from 1.1±0.8 to 0.4±0.2 ( P =0.0002). Efficiency improved at rest (72.9±5.8% versus 83.5±5.7%; P <0.00001) and during handgrip (63.5±7.8% versus 78.9±7.1%; P <0.00001). In hypertensive patients, optimal brachial and central blood pressure reduction shifts arterioventricular coupling from cardiac output maximization to ventricular mechanical efficiency optimization. This occurs before significant changes in ventricular geometry and may be responsible for early clinical improvements.

Background The early diastolic velocity of the mitral annulus (E′) is reduced in patients with diastolic dysfunction and increased filling pressures. Because transmitral inflow early velocity (E) increases progressively with higher filling pressures, E/E′ has been shown to have a strong positive relationship with pulmonary capillary wedge pressure (PCWP) and left ventricular end-diastolic pressure. However, previous studies have primarily involved patients without a pericardial abnormality. In constrictive pericarditis (CP), E′ is not reduced, despite increased filling pressures. This study evaluated the relationship between E/E′ and PCWP in patients with CP. Methods and Results We studied 10 patients (8 men; mean age, 64±7 years) with surgically confirmed CP. Doppler echocardiography was performed to measure early and late diastolic transmitral flow velocities. Tissue Doppler echocardiography was performed to measure E′. PCWP was measured with right heart catheterization. All patients were in sinus rhythm. Mean E and E′ were 91±15 cm/s and 11±4 cm/s, respectively. Mean PCWP was 25±6 mm Hg. E′ was positively correlated with PCWP ( r =0.69, P =0.027). There was a significant inverse correlation between E/E′ and PCWP ( r =−0.74, P =0.014). Despite high left ventricular filling pressures, E/E′ (mean, 9±4) was <15 in all but 1 patient. Conclusions Paradoxical to the positive correlation between E/E′ and PCWP in patients with myocardial disease, an inverse relationship was found in patients with CP.

Background —Clinical applicability of conventional ultrasonographic systems using mechanical adapters for 3D echocardiographic imaging has been limited by long acquisition and processing times. We developed a rapid (6-s) acquisition technique that collects apical tomograms using a continuously internally rotating transthoracic transducer. This study was performed to examine the clinical feasibility of rapid-acquisition 3D echocardiography to estimate left ventricular end-diastolic and end-systolic volumes using electron-beam computed tomography as the reference standard. Methods and Results —We collected a series of 6 to 11 apical echocardiographic tomograms, depending on heart rate, in 11 patients. There was good correlation, low variability, and low bias between rapid 3D echocardiography and electron-beam computed tomography for measuring left ventricular end-diastolic volume ( r =0.96; standard error of the estimate, 21.34 mL; bias, −4.93 mL) and left ventricular end-systolic volume ( r =0.96; standard error of the estimate, 14.78 mL; bias, −6.97 mL). Conclusions —The rapid-acquisition 3D echocardiography extends the use of a multiplane, internally rotating handheld transducer so that it becomes a precise and clinically feasible tool for assessing left ventricular volumes and function. A rapid-image acquisition time of 6 s would allow repeated image collection during the course of a clinical echocardiographic examination. Additional work must address rapid and automated data processing.