Clarence Shub

Echocardiographically documented mitral-valve prolapse. Long-term follow-up of 237 patients.

We determined the long-term prognosis for patients with mitral-valve prolapse documented by echocardiography by following 237 minimally symptomatic or asymptomatic patients for a mean of 6.2 years (range, 1 to 10.4). The actuarial eight-year probability of survival was 88 per cent, which is not significantly different from that for a matched control population. An initial left ventricular diastolic dimension exceeding 60 mm was the best echocardiographic predictor of the subsequent need for mitral-valve replacement (17 patients). Of the 97 patients with redundant mitral-valve leaflets identified echocardiographically, 10 (10.3 per cent) had sudden death, infective endocarditis, or a cerebral embolic event; in contrast, of the 140 patients with nonredundant valves, only 1 (0.7 per cent) had such complications (P less than 0.001). Most patients with echocardiographic evidence of mitral-valve prolapse have a benign course, but subsets at high risk for the development of progressive mitral regurgitation, sudden death, cerebral embolic events, or infective endocarditis can be identified by echocardiography.

Natural history of asymptomatic mitral valve prolapse in the community.

Background—The outcome of mitral valve prolapse (MVP) is controversial, with marked discrepancies in reported complication rates. Methods and Results—We conducted a community study of all Olmsted County, Minn, residents first diagnosed with asymptomatic MVP between 1989 and 1998 (N=833). Diagnosis, motivated by auscultatory findings (n=557) or incidental (n=276), was always confirmed by echocardiography with the use of current criteria. End points analyzed during 4581 person-years of follow-up were mortality (n=96, 19±2% at 10 years), cardiovascular morbidity (n=171), and MVP-related events (n=109, 20±2% at 10 years). The most frequent primary risk factors for cardiovascular mortality were mitral regurgitation from moderate to severe (P =0.002, n=131) and, less frequently, ejection fraction <50% (P =0.003, n=31). Secondary risk factors independently predictive of cardiovascular morbidity were slight mitral regurgitation, left atrium ≥40 mm, flail leaflet, atrial fibrillation, and age ≥50 years (all P <0.01). Patients with only 0 or 1 secondary risk factor (n=430) had excellent outcome, with 10-year mortality of 5±2% (P =0.17 versus expected), cardiovascular morbidity of 0.5%/y, and MVP-related events of 0.2%/y. Patients with ≥2 secondary risk factors (n=250) had mortality similar to expected (P =0.20) but high cardiovascular morbidity (6.2%/y, P <0.01) and notable MVP-related events (1.7%/y, P <0.01). Patients with primary risk factors (n=153) showed excess 10-year mortality (45±9%, P =0.01 versus expected), high morbidity (18.5%/y, P <0.01), and high MVP-related events (15%/y, P <0.01). Conclusions—Natural history of asymptomatic MVP in the community is widely heterogeneous and may be severe. Clinical and echocardiographic characteristics allow separation of the majority of patients with excellent prognosis from subsets of patients displaying, during follow-up, high morbidity or even excess mortality as direct a consequence of MVP.

Risk of Patients With Severe Aortic Stenosis Undergoing Noncardiac Surgery

Aortic stenosis (AS) is a major risk factor for perioperative cardiac events in patients undergoing noncardiac surgery. We previously showed that selected patients with AS who were not candidates for, or refused, aortic valve replacement could undergo noncardiac surgery with acceptable risk. We extended our previous experience over a subsequent 5-year period by retrospectively analyzing the perioperative course of all patients with severe AS (aortic valve area index < 0.5 cm2/m2 or mean gradient > 50 mm Hg), determined with Doppler echocardiography or cardiac catheterization, who underwent noncardiac surgery. Nineteen patients underwent 28 surgical procedures: 22 elective and 6 emergency. The types of these procedures were 12 orthopedic, 6 intraabdominal, 4 vascular, 4 urologic, 1 otolaryngologic, and 1 thoracic. Mean age was 75 +/- 8 years. Of the 19 patients, 16 (84%) had > or = 1 symptom: dyspnea, angina, syncope, or presyncope. Mean left ventricular ejection fraction was 61 +/- 11%. The type of anesthesia was general in 26 procedures and continuous spinal in 2. Intraarterial monitoring of blood pressure was used in 20 of the 28 surgical procedures. Intraoperative hypotensive events were treated promptly, primarily with phenylephrine. In all cases the anesthesia team was aware of the severity of the AS and integrated this into the anesthetic plan. Two patients (elective operation in 1 and emergency in 1) had complicated postoperative courses and died. There were no other intraoperative or postoperative events in any of the other patients. Although aortic valve replacement remains the primary treatment for patients with severe AS, selected patients with severe AS, who are otherwise not candidates for aortic valve replacement, can undergo noncardiac surgery with acceptable risk when appropriate intraoperative and postoperative management is used.

Role of two-dimensional echocardiography in the prediction of in-hospital complications after acute myocardial infarction

To evaluate prospectively the prognostic value of two-dimensional echocardiography after acute myocardial infarction, two-dimensional echocardiography was performed on 61 consecutive patients who were admitted to the hospital with this condition. A left ventricular wall motion score index was derived from analysis of regional wall motion; an index of 2.0 or more within 12 hours of admission identified patients at high risk for pump failure, malignant ventricular arrhythmia or death. These complications occurred in 24 of 27 patients with an initial wall motion score index of 2.0 or more, but in only 6 of 34 with an initial index of less than 2.0 (p less than 0.0005). Of the 47 patients who were in Killip class I on admission, complications developed in 11 (79%) of the 14 with an initial index of 2.0 or more, but in only 6 (18%) of the 33 with an initial index of less than 2.0. After acute myocardial infarction, early determination of the wall motion score index by two-dimensional echocardiography is useful for identifying patients at high risk for complications and is especially valuable in the subset of patients who initially seem to be in stable condition as judged from clinical variables.

Accuracy of 2-dimensional echocardiographic diagnosis of congenitally bicuspid aortic valve: Echocardiographic-anatomic correlation in 115 patients

The preoperative 2-dimensional (2-D) echocardiograms of all patients less than 50 years of age in whom the aortic valve had been directly inspected by the surgeon or the pathologist or both were reviewed. From June 1977 to June 1981, 283 patients aged less than or equal to 50 years had aortic valve surgery at the Mayo Clinic: 115 (aged 1 to 50 years [mean 32]) had 2-D examinations preoperatively. The echocardiograms were reviewed blindly, and the aortic valve structure was categorized as bicuspid, tricuspid, or indeterminate. On the basis of combined surgical and pathologic inspection, 50 aortic valves were congenitally bicuspid, 60 were tricuspid, 4 were unicommissural, and 1 was quadricuspid. By 2-D echocardiography, the number of cusps was indeterminate in 29 patients (25%). When these patients were excluded, the sensitivity, specificity, and diagnostic accuracy of 2-D echocardiography for bicuspid aortic valve were 78,96, and 93%, respectively. Thus, with adequate 2-D images, echocardiography is a sensitive and highly specific technique for the diagnosis of bicuspid aortic valve.

Two-dimensional echocardiographic calculation of left ventricular mass as recommended by the American Society of Echocardiography: Correlation with autopsy and M-mode echocardiography

The American Society of Echocardiography (ASE) has recommended diastolic area length and truncated ellipsoid methods for estimating left ventricular (LV) mass by two-dimensional (2D) echocardiography. The major goals of this retrospective study were to (1) assess the correlation between ASE-recommended 2D and M-mode echo-derived measurements of LV mass, (2) compare the two ASE-recommended 2D echocardiography methods, and (3) compare the echo-derived LV mass with anatomic LV mass. The study included 2D echocardiograms obtained within 30 days of death from 34 patients who subsequently underwent autopsy and 2D echocardiograms of 56 normal subjects. The formula used for measurement of M-mode echo-derived LV mass was LV mass = 0.8 (ASE-cube LV mass) + 0.6 gm. For 2D echo-derived LV mass, the ASE-recommended area length and truncated ellipsoid methods in systole and diastole were used, with and without incorporating the papillary muscles into the myocardial shell. LV mass derived by M-mode echocardiography was comparable to that derived by 2D methods, and it is reasonable to use this technique for normally shaped ventricles. When the papillary muscles were included into the myocardial shell, diastolic 2D methods overestimated autopsy LV mass. Both diastolic area length and truncated ellipsoid methods were comparable to autopsy LV mass. When the papillary muscles were excluded, the systolic area length method showed the best agreement with autopsy LV mass.

Creatine kinase release after successful percutaneous transluminal coronary angioplasty

After successful percutaneous transluminal coronary angioplasty (PTCA), 25 (20%) of 128 patients had elevation of creatine kinase MB isoenzyme (CK-MB). The increase was mild (mean 9% MB with total creatine kinase of 179 U/L). Three variables were significantly related to the enzyme elevation: chest pain, small branch vessel occlusion, and recent myocardial infarction. Of the patients with CK-MB elevation, 60% experienced chest pain and 32% sustained a small branch vessel occlusion during PTCA, compared with 11% and 8%, respectively, of the 103 patients without enzyme elevation (p less than 0.001 and p less than 0.01). Of 16 patients with recent myocardial infarction, seven (44%) had release of CK-MB. Although mild enzyme elevation after successful PTCA is likely due to a small amount of myocardial necrosis, this phenomenon was not associated with increased cardiac morbidity or mortality. Therefore, release of CK-MB without other clinical evidence for myocardial infarction after successful PTCA does not in itself warrant longer hospitalization, and routine serial enzyme determinations are probably unnecessary. By reducing the number of laboratory tests and the duration of hospitalization, the cost effectiveness of PTCA may be increased.

Prognostic value of predischarge 2-dimensional echocardiogram after acute myocardial infarction

The prognostic value of a 2-dimensional echocardiogram (2-D echo) was determined in 46 patients (32 men and 14 women) who survived an acute myocardial infarction (MI) from November 1979 to December 1980. The mean age of the patients was 61 years (range 36 to 92). The MI was anterior in 21, inferior in 22 and indeterminate in 3; it was transmural in 31 and nontransmural in 15. A 2-D echo was obtained 10 to 15 days after the MI--that is, 1 to 3 days before hospital discharge. A wall motion score index (WMSI) was derived with the use of a 14-segment model of the left ventricle. Each segment was assigned a number corresponding to its wall motion (0 = hyperkinetic, 1 = normal, 2 = hypokinetic, 3 = akinetic, 4 = dyskinetic and 5 = aneurysm) and the WMSI was calculated by dividing the sum of these numbers by the number of segments visualized (1.0 = normal wall motion). During a mean follow-up of 21 months (range 15 to 28), 17 patients had a complication: death, recurrence of MI, congestive heart failure of New York Heart Association class III or IV, or angina graded New York Heart Association class III or IV. Patients with compared to those without complications had a significantly higher WMSI (2.2 +/- 0.4 and 1.7 +/- 0.5, p less than 0.005). The difference in WMSI between those who died and those who survived was not significant because of the small number of deaths.(ABSTRACT TRUNCATED AT 250 WORDS)

Sensitivity of two-dimensional echocardiography in the direct visualization of atrial septal defect utilizing the subcostal approach: Experience with 154 patients

In the standard precordial echocardiographic imaging planes, there is frequent dropout of atrial septal echoes in the region of the fossa ovalis that can be minimized by use of the subcostal imaging approach. The diagnostic sensitivity of this approach was reviewed in 154 patients (mean age 31 years, range 2 months to 74 years) with documented atrial septal defect in whom a satisfactory image of the atrial septum could be obtained. Subcostal two-dimensional echocardiography successfully visualized 93 (89%) of the 105 ostium secundum atrial septal defects, all 32 (100%) ostium primum defects and 7 (44%) of the 16 sinus venosus defects. A defect was not visualized (false negative response) in 12 patients (11%) with an ostium secundum defect and in 9 patients (56%) with a sinus venosus defect. In three of the former and five of the latter, a two-dimensional echocardiographic contrast examination established the presence of the interatrial shunt. Twenty-four patients (16%) with clinical findings of uncomplicated atrial septal defect confirmed by two-dimensional echocardiography underwent surgical repair of the defect without preoperative cardiac catheterization. There were no perioperative complications. Two-dimensional echocardiographic examination of the atrial septum utilizing the subcostal approach is the preferred method for the confident, noninvasive diagnosis and categorization of atrial septal defects. Two-dimensional echocardiographic contrast and Doppler examinations complement the technique and enhance diagnostic accuracy.

Risk of noncardiac surgical procedures in patients with aortic stenosis

Although severe aortic stenosis has been reported to increase the risk of noncardiac operation, recent advances in anesthetic management may alter this risk. We reviewed the perioperative course of 48 consecutive patients (mean age, 73 years) with significant aortic stenosis who underwent a noncardiac operation or diagnostic procedure between 1985 and 1987. Twenty-five patients had local anesthesia with intravenous sedation, 22 (17 with severe and 5 with moderate aortic stenosis) underwent general anesthesia, and I had spinal anesthesia. Of the 48 patients, 36 (75%) had symptoms—congestive heart failure in 24, angina in 19, and syncope in 7. Doppler echocardiography, performed in all 48 patients, revealed a mean peak instantaneous gradient of 76 mm Hg and a calculated aortic valve area (in 22 patients) of 0.61 cm 2 . In the 20 patients who also underwent preoperative cardiac catheterization, the calculated mean aortic valve area was 0.59 cm 2 . Seven patients had one or more perioperative events, including intraoperative hypotension in five; all except one of these events were transient and without major sequelae. No intraoperative deaths occurred. Selected patients with severe aortic stenosis can undergo noncardiac procedures at a reasonably low risk with careful monitoring of anesthesia.