Clinical evaluation versus Doppler echocardiography in the quantitative assessment of valvular heart disease

Balloon mitral valvuloplasty in low gradient severe rheumatic mitral stenosis: Immediate and short-term outcomes

Background

Efficacy of balloon mitral valvuloplasty (BMV) in low gradient severe rheumatic mitral stenosis (MS) is not very well defined. This study was undertaken to evaluate the outcomes of BMV in low gradient severe rheumatic MS.

Methods

Severe MS was defined as mitral valve area < 1.5 cm2. Low gradient was defined as mean diastolic trans-mitral gradient (MG) < 10 mmHg and low flow as stroke volume index < 35 ml/m2 on echocardiography. Sixty patients were divided into normal-flow/low-gradient (NFLG) (40) and low-flow/low-gradient (LFLG) (20) groups. Post-BMV parameters were recorded after 72 h and at the end of one year.

Results

Mean age was 36.2 ± 6.6 years in NFLG group and 40.6 ± 2.6 years in LFLG group (p < 0.01) and females were 75 % (n = 30) in NFLG group as compared to 60 % (n = 12) in LFLG group. Patients in the LFLG group had higher Wilkins score (p < 0.02) and prevalence of atrial fibrillation (n = 8, 40 %) as compared to NFLG group (n = 7, 17.5 %; p < 0.01). A greater decrease in MG was observed in NFLG group (p < 0.01), whereas increase in MVA was comparable in both the groups (p > 0.05). Ninety percent (n = 36) patients improved in NFLG group in comparison to 70 % (n = 14) in LFLG group (p < 0.01). At the end of one-year, symptomatic improvement persisted in all patients who became asymptomatic post-BMV.

Conclusion

Symptomatic improvement following BMV was better seen in NFLG group because of greater decrease in MG in comparison to LFLG group. Results of BMV were suboptimal in LFLG group because of higher sub-valvular obstruction, increased age and higher prevalence of AF.

Self-learning of cardiac ultrasound by medical students: can augmented online training improve and maintain manual POCUS skills over time?

BACKGROUND

The use of cardiac point of care ultra-sound is rapidly growing and so is the demand for quality POCUS teaching. POCUS teaching is usually conducted in small groups requiring much space and equipment. This study attempts to test whether providing access to an E-learning module as an adjunct to a cardiac POCUS course can increase students' image acquisition skills. This will show POCUS teaching can improve significantly without having to invest a significant amount of resources.

METHODS

Medical students (N = 125) were divided into two groups and had undergone a hands-on Cardiac POCUS course before their internal clerkship. During the clerkship, members of both groups got to practice their POCUS skills in the internal wards. One group was provided with accounts to a cardiac POCUS teaching E-learning platform (eMedical Academy©). After limited time for self- practice, both groups underwent a pre-validated ultrasound examination. The two groups' test results were then compared for each POCUS view and for the total exam score.

RESULTS

The E-learning group performed significantly better than the course-only group in the 6-min exam total score, and at acquiring the following views: parasternal long axis view, apical four-chamber view, and the inferior vena cava view.

CONCLUSION

E-learning platforms can be an efficient tool for improving cardiac POCUS teaching and maintaining POCUS skills. Using it as a supplement to a hands-on course provides better POCUS skills without the need of extra hands-on teaching.

Algorithm for predicting valvular heart disease from heart sounds in an unselected cohort

Objective

This study aims to assess the ability of state-of-the-art machine learning algorithms to detect valvular heart disease (VHD) from digital heart sound recordings in a general population that includes asymptomatic cases and intermediate stages of disease progression.

Methods

We trained a recurrent neural network to predict murmurs from heart sound audio using annotated recordings collected with digital stethoscopes from four auscultation positions in 2,124 participants from the Tromsø7 study. The predicted murmurs were used to predict VHD as determined by echocardiography.

Results

The presence of aortic stenosis (AS) was detected with a sensitivity of 90.9%, a specificity of 94.5%, and an area under the curve (AUC) of 0.979 (CI: 0.963-0.995). At least moderate AS was detected with an AUC of 0.993 (CI: 0.989-0.997). Moderate or greater aortic and mitral regurgitation (AR and MR) were predicted with AUC values of 0.634 (CI: 0.565-703) and 0.549 (CI: 0.506-0.593), respectively, which increased to 0.766 and 0.677 when clinical variables were added as predictors. The AUC for predicting symptomatic cases was higher for AR and MR, 0.756 and 0.711, respectively. Screening jointly for symptomatic regurgitation or presence of stenosis resulted in an AUC of 0.86, with 97.7% of AS cases (n = 44) and all 12 MS cases detected.

Conclusions

The algorithm demonstrated excellent performance in detecting AS in a general cohort, surpassing observations from similar studies on selected cohorts. The detection of AR and MR based on HS audio was poor, but accuracy was considerably higher for symptomatic cases, and the inclusion of clinical variables improved the performance of the model significantly.

Screening for the prevalence of rheumatic heart disease among school children in Egypt

BACKGROUND

In low-income nations, Rheumatic valvular heart disease remains a major cause of morbidity and premature deaths. Accurate prevalence data in Egypt are still lacking yet highly desirable to facilitate health care planning.

METHODOLOGY

An cluster sample of school children in eastern Egyptian Governorates was examined clinically and echocardiographically (using abbreviated protocol) for detection of rheumatic valvular heart disease based on 2012 World Heart Federation criteria (the Doppler and the morphological criteria) for diagnosis. According to echocardiography interpretation, participants were categorized as having definite rheumatic heart disease (RHD), borderline RHD or no RHD.

RESULTS

A total of 1680 students aged between 6 and 18 years were screened, 119 echocardiographic studies were non-interpretable; so, a total of 1560 studies were evaluated. From the total screened students, 1560 studies were adequate and interpretable according to the criteria specified in the methods section. This revealed a prevalence of 2.3% of the sample with RHD without adding the equivocal cases. The most prevalent lesion as detected by echocardiography was mitral regurgitation (29% of definite RHD cases).

CONCLUSION

Rheumatic valvular heart disease remains prevalent in Egypt and the findings of this study should influence early detection, primary and secondary prevention, and adequate future national health plans.

Fast and Robust Clutter Filtering in Ultrafast Echocardiography

Singular value decomposition (SVD)-based filters have become the norm for clutter filtering in ultrasound blood flow applications but are computationally expensive and susceptible to large and fast tissue motion. Randomized SVD (rSVD) has later been shown to successfully accelerate filtering of in vivo stationary tissues. However, little is known about its performance on ultrafast echocardiography, which produces thousands of frames to assess complex myocardial deformation and blood dynamics. Neither has its inherently robust randomized scheme been proven in any ultrasound blood flow imaging methods. This study thus proposed to employ rSVD as a fast and robust clutter filter for ultrafast echocardiograms prior to power Doppler analysis. Ultrafast echocardiograms of nine normal human hearts were acquired in vivo by our cascaded synthetic aperture imaging method. One subject was additionally scanned under four different sonographic signal-to-noise ratio (SNR) levels. Contrast ratio (CR) and contrast-to-noise ratio (CNR) of in vivo power Doppler images obtained from filtered ultrafast echocardiograms were calculated, and their mean and standard deviation within a cardiac cycle represented temporal average and variation of contrast resolution, respectively. Our in vivo results showed that rSVD accelerated clutter filtering by 12-fold and provided significantly better local contrast (mean CNR values: p < 0.001) while being equally effective (mean CR values: p = 0.20) compared with full-SVD. rSVD yielded smaller standard deviations of CR (1.32 dB vs. 5.49 dB) and CNR (1.27 dB vs. 5.49 dB) than full-SVD in the lowest SNR scenario, thus substantiating its superior robustness. Our findings suggest using rSVD in ultrafast echocardiographic blood dynamics analysis.

Using Point-of-Care Ultrasound in Heart Failure Diagnosis and Management in Rural and Resource-Limited Settings

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RHD is a common cause of heart failure in sub-Saharan Africa.

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Task shifting by training rural providers in POCUS improves cardiac imaging access.

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POCUS in low-resource settings can determine presence of structural heart disease.

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There are specific POCUS device considerations for use in low-resource settings.

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POCUS use in rural low-resource settings can lead to early heart failure management.

Differences in Cardiac Remodeling in Left-Sided Valvular Regurgitation: Implications for Optimal Definition of Significant Aortic Regurgitation

BACKGROUND

Grading of aortic regurgitation (AR) and mitral regurgitation (MR) is similar in the cardiology guidelines despite distinct differences in left ventricular (LV) adaptive pathophysiology.

OBJECTIVES

This study compared differences in LV remodeling in patients with similar degrees of AR and MR severity and evaluated optimal cutoffs for significant AR in relation to the outcome of aortic valve replacement or repair (AVR) during follow-up.

METHODS

From 2008 to 2018, consecutive patients with isolated AR or MR who had cardiovascular magnetic resonance (CMR) were identified and CMR parameters were compared. Patients with left ventricular ejection fraction (LVEF) <50%, ischemic scar >5%, valve stenosis, or concomitant regurgitation were excluded. Patients were followed longitudinally for AVR.

RESULTS

Baseline characteristics of isolated AR (n = 418) and isolated MR (n = 1,073) were comparable except for higher male proportion and hypertension in AR, while heart failure was more prevalent in MR. Indexed LV end-diastolic and end-systolic volumes and mass were higher in AR compared with MR at the same level of regurgitant fraction. During follow-up (mean 2.1 years), 18.7% of AR patients underwent AVR based on symptoms or LV remodeling. Interestingly, 38.0% of patients that underwent AVR within 3 months after CMR did not meet severe AVR by current guidelines of AR severity. AR regurgitant fraction>35% had high sensitivity (86%) and specificity (88%) for identifying patients who underwent AVR.

CONCLUSIONS

For similar regurgitation severity, LV remodeling is different in AR compared with MR. Cardiac symptoms and significant LV remodeling in AR requiring AVR occur frequently in patients with less severity than currently proposed. The study findings suggest that the optimal threshold for severe AR with CMR is different than MR and is lower than currently stated in the guidelines.

Computed Tomography-Based Assessment of Transvalvular Pressure Gradient in Aortic Stenosis

Background: In patients with aortic stenosis, computed tomography (CT) provides important information about cardiovascular anatomy for treatment planning but is limited in determining relevant hemodynamic parameters such as the transvalvular pressure gradient (TPG).

Purpose: In the present study, we aimed to validate a reduced-order model method for assessing TPG in aortic stenosis using CT data.

Methods: TPG_CT was calculated using a reduced-order model requiring the patient-specific peak-systolic aortic flow rate (Q) and the aortic valve area (AVA). AVA was determined by segmentation of the aortic valve leaflets, whereas Q was quantified based on volumetric assessment of the left ventricle. For validation, invasively measured TPG_catheter was calculated from pressure measurements in the left ventricle and the ascending aorta. Altogether, 84 data sets of patients with aortic stenosis were used to compare TPG_CT against TPG_catheter.

Results: TPG_catheter and TPG_CT were 50.6 ± 28.0 and 48.0 ± 26 mmHg, respectively (p = 0.56). A Bland–Altman analysis revealed good agreement between both methods with a mean difference in TPG of 2.6 mmHg and a standard deviation of 19.3 mmHg. Both methods showed good correlation with r = 0.72 (p < 0.001).

Conclusions: The presented CT-based method allows assessment of TPG in patients with aortic stenosis, extending the current capabilities of cardiac CT for diagnosis and treatment planning.

Cardiac auscultation poorly predicts the presence of valvular heart disease in asymptomatic primary care patients

Objective

Cardiac auscultation is a key clinical skill, particularly for the diagnosis of valvular heart disease (VHD). However, its utility has declined due to the widespread availability of echocardiography and diminishing emphasis on the importance of clinical examination. We aim to determine the contemporary accuracy of auscultation for diagnosing VHD in primary care.

Methods

Cardiac auscultation was undertaken by one of two experienced general practitioners (primary care/family doctors) in a subset of 251 asymptomatic participants aged >65 years undergoing echocardiography within a large community-based screening study of subjects with no known VHD. Investigators were blinded to the echocardiographic findings. Newly detected VHD was classified as mild (mild regurgitation of any valve or aortic sclerosis) or significant (at least moderate regurgitation or mild stenosis of any valve).

Results

Newly identified VHD was common, with mild disease in 170/251 participants (68%) and significant disease in 36/251 (14%). The sensitivity of auscultation was low for the diagnosis of mild VHD (32%) but slightly higher for significant VHD (44%), with specificities of 67% and 69%, respectively. Likelihood ratios were not statistically significant for the diagnosis of either mild or significant VHD in the overall cohort, but showed possible value for auscultation in non-overweight subjects (body mass index <25 kg/m2).

Conclusion

Cardiac auscultation has limited accuracy for the detection of VHD in asymptomatic patients and is a poor diagnostic screening tool in primary care, particularly for overweight subjects. Ensuring easy access to echocardiography in patients with symptoms suggesting VHD is likely to represent a better diagnostic strategy.

The feasibility and efficacy of implementing a focused cardiac ultrasound course into a medical school curriculum

BACKGROUND

Teaching cardiac ultrasound to medical students in a brief course is a challenge. We aimed to evaluate the feasibility of teaching large groups of medical students the acquisition and interpretation of cardiac ultrasound images using a pocket ultrasound device (PUD) in a short, specially designed course.

METHODS

Thirty-one medical students in their first clinical year participated in the study. All were novices in the use of cardiac ultrasound. The training consisted of 4 hours of frontal lectures and 4 hours of hands-on training. Students were encouraged to use PUD for individual practice. Finally, the students' proficiency in the acquisition of ultrasound images and their ability to recognize normal and pathological states were evaluated.

RESULTS

Sixteen of 27 (59%) students were able to demonstrate all main ultrasound views (parasternal, apical, and subcostal views) in a six-minute test. The most obtainable view was the parasternal long-axis view (89%) and the least obtainable was the subcostal view (58%). Ninety-seven percent of students correctly differentiated normal from severely reduced left ventricular function, 100% correctly differentiated a normal right ventricle from a severely hypokinetic one, 100% correctly differentiated a normal mitral valve from a rheumatic one, and 88% correctly differentiated a normal aortic valve from a calcified one, while 95% of them correctly identified the presence of pericardial effusion.

CONCLUSIONS

Training of medical students in cardiac ultrasound during the first clinical year using a short, focused course is feasible and enables students with modest ability to acquire the main transthoracic ultrasound views and gain proficiency in the diagnosis of a limited number of cardiac pathologies.

Discrepancies between direct catheter and echocardiography-based values in aortic stenosis

OBJECTIVES

The goal of this article is to examine the correlation of catheter (cath) based and echocardiographic assessment of aortic stenosis (AS) in a community-based academic hospital setting, particularly in the degree that decision to refer for surgery is altered.

BACKGROUND

Current guidelines discourage AS evaluation by invasive pressure measurement if echocardiography (echo) is adequate, but several studies show sizable differences between echo and cardiac catheterization lab (CCL) measurements. We examine this correlation using high quality CCL techniques.

METHODS

Sequential patients with suspected AS by echo (n = 40) aged 61-94 underwent catheterization with pressure gradients via left ventricular pressure wire and ascending aorta catheter. The echos leading to the catheterization were independently reviewed by an expert panel to assess the quality of community-based readings.

RESULTS

CCL changed assessment of severity of aortic valve area (AVA) by more than 0.3 cm(2) in 25% and 0.5 cm(2) in 8%. Values changed to over or under the surgical threshold of AVA < 1 cm(2) in 30% of the patients. Pearson correlation of 0.35 between measurements of AVA by echo and CCL is lower than earlier studies, which often reported correlation values of 0.90 or greater. Echo expert reviews provided minimal improvement in discrepancies (Pearson correlation of 0.46), suggesting quality of initial interpretation was not the issue.

CONCLUSIONS

Cath-echo correlation of AS severity is lower in contemporaneous practice than previously assumed. This can alter the decision for aortic valve replacement. Sole reliance on echo-derived assessment of AS may at times be problematic.

Doppler-detected valve movement in aortic stenosis: a predictor of adverse outcome

BACKGROUND

The absence of auscultatory aortic valve closure sound is associated with severe aortic stenosis. The absence of Doppler-derived aortic opening (Aop ) or closing (Acl ) may be a sign of advanced severe aortic stenosis.

HYPOTHESIS

Absent Doppler-detected Aop or Acl transient is indicative of very severe aortic stenosis and is associated with adverse outcome.

METHODS

A total of 118 consecutive patients with moderate (n = 63) or severe aortic stenosis (n = 55) were included. Aop and Acl signals were identified in a blinded fashion by continuous-wave Doppler. Patients with and without Aop and Acl were compared using χ(2) test for dichotomous variables and analysis of variance for continuous variables. The associations of Aop and Acl with aortic valve replacement were determined.

RESULTS

Aop or Acl were absent in 22 of 118 patients. The absence of Aop or Acl was associated with echocardiographic parameters of severe aortic stenosis. The absence of Aop or Acl was associated with incident aortic valve replacement (36.4% vs 7.3%, respectively, P < 0.001). Even in patients with aortic valve area <1 cm(2) , the absence of Aop or Acl was still associated with increased rate of aortic valve replacement (42.1% vs 13.9%, respectively, P = 0.019) and provided incremental predictive value over peak velocity.

CONCLUSIONS

In a typical population of patients with aortic stenosis, approximately 1 in 6 has no detectible aortic valve opening or closing Doppler signal. The absence of an Aop or Acl signal is a highly specific sign of severe aortic stenosis and is associated with incident aortic valve replacement.

Clinical, laboratory and echocardiographic profile of acute rheumatic fever in Nepali children

BACKGROUND

Acute rheumatic fever (RF) is a common, preventable health problem in developing countries. Sporadic outbreaks and the prevalence in some indigenous populations have renewed interest in RF in developed countries also.

AIMS

To describe the clinical, laboratory and echocardiographic features, outcome and value of echocardiography in detecting valvular disease in RF.

METHODS

A prospective, cross-sectional study was conducted over 2 years. Patients under 14 years admitted to the cardiology unit of Kanti Children's Hospital, Kathmandu with RF using the Jones criteria were recruited consecutively.

RESULTS

The median age (range) of the 51 patients was 11 (5-14) years, the male:female ratio was 1.6:1 and 39% had a history of a sore throat. Clinical and laboratory features detected were as follows: carditis 92%, arthritis 33%, chorea 8%, subcutaneous nodules 4%, fever 51%, arthralgia 37%, elevated antistreptolysin O titre 94%, elevated CRP 78%, prolonged PR interval 45%, pericardial effusion 22% and cardiac failure 28%. In total, 36 patients (71%) complained of joint pains. A murmur on auscultation was significantly associated with underlying diseased valves confirmed by echocardiography (p=0.001). A murmur was audible in 78.4% and diseased valves were confirmed by echocardiography in 88.2%. The mitral valve was the most commonly involved valve (82%) and mitral regurgitation the commonest lesion (24%). A thickened mitral valve predicted carditis (p=0.007). Five (10%) patients died.

CONCLUSION

Inclusion of echocardiographic evidence of carditis and possibly arthralgia as major criteria would improve case detection.

Screening for rheumatic heart disease in Aboriginal and Torres Strait Islander children

Rheumatic heart disease is preventable but causes significant morbidity and mortality in Aboriginal Australian and Torres Strait Islander populations. Screening echocardiography has the potential to detect early rheumatic heart disease thereby enabling timely commencement of treatment (secondary prophylaxis) to halt disease progression. However, a number of issues prevent echocardiographic screening for rheumatic heart disease satisfying the Australian criteria for acceptable screening programs. Primarily, it is unclear what criteria should be used to define a positive screening result as questions remain regarding the significance, natural history and potential treatment of early and subclinical rheumatic heart disease. Furthermore, at present the delivery of secondary prophylaxis in Australia remains suboptimal such that the potential benefits of screening would be limited. Finally, the impact of echocardiographic screening for rheumatic heart disease on local health services and the psychosocial health of patients and families are yet to be ascertained.

Rheumatic heart disease: progress and challenges in India

Rheumatic heart disease, a neglected disease, continues to be a burden in India and other developing countries. It is a result of an autoimmune sequalae in response to group A beta hemolytic streptococcus (GAS) infection of the pharynx. Acute rheumatic fever (RF), a multisystem inflammatory disease, is followed by rheumatic heart disease (RHD) and has manifestations of joints, skin and central nervous system involvement. A review of epidemiological studies indicates unchanged GAS pharyngitis and carrier rates in India. The apparent decline in RHD rates in India as indicated by the epidemiological studies has to be taken with caution as methodological differences exist among studies. Use of echocardiography increases case detection rates of RHD in population surveys. However, the significance of echo based diagnosis of carditis needs further evaluation to establish the significance. Research in this area through prospective follow up studies will have to be undertaken by the developing countries as the interest of developed countries in the disease has waned due the declined burden in their populations. Prevention of RHD is possible through treatment of GAS pharyngitis (primary prophylaxis) and continued antibiotic treatment for number of years in patients with history of RF to prevent recurrences (secondary prophylaxis). The cost effectiveness and practicality of secondary prophylaxis is well documented. The challenge to any secondary prophylaxis program for prevention of RF in India will be the availability of benzathine penicillin G and dissipation of fears of allergic reactions to penicillin among practitioners, general public and policy makers. The authors review here the progress and challenges in epidemiology, diagnosis and primary and secondary prevention of RF and RHD.

Optimising echocardiographic screening for rheumatic heart disease in New Zealand: not all valve disease is rheumatic

AIMS

Echocardiography detects a greater prevalence of rheumatic heart disease than heart auscultation. Echocardiographic screening for rheumatic heart disease combined with secondary prophylaxis may potentially prevent severe rheumatic heart disease in high-risk populations. We aimed to determine the prevalence of rheumatic heart disease in children from an urban New Zealand population at high risk for acute rheumatic fever.

METHODS AND RESULTS

To optimise accurate diagnosis of rheumatic heart disease, we utilised a two-step model. Portable echocardiography was conducted on 1142 predominantly Māori and Pacific children aged 10-13 years. Children with an abnormal screening echocardiogram underwent clinical assessment by a paediatric cardiologist together with hospital-based echocardiography. Rheumatic heart disease was then classified as definite, probable, or possible. Portable echocardiography identified changes suggestive of rheumatic heart disease in 95 (8.3%) of 1142 children, which reduced to 59 (5.2%) after cardiology assessment. The prevalence of definite and probable rheumatic heart disease was 26.0 of 1000, with 95% confidence intervals ranging from 12.6 to 39.4. Portable echocardiography overdiagnosed rheumatic heart disease with physiological valve regurgitation diagnosed in 28 children. A total of 30 children (2.6%) had non-rheumatic cardiac abnormalities, 11 of whom had minor congenital mitral valve anomalies.

CONCLUSIONS

We found high rates of undetected rheumatic heart disease in this high-risk population. Rheumatic heart disease screening has resource implications with cardiology evaluation required for accurate diagnosis. Echocardiographic screening for rheumatic heart disease may overdiagnose rheumatic heart disease unless congenital mitral valve anomalies and physiological regurgitation are excluded.

Evaluation of a screening protocol using auscultation and portable echocardiography to detect asymptomatic rheumatic heart disease in Tongan schoolchildren

BACKGROUND

Rheumatic heart disease (RHD) is an important problem in developing countries; however, many cases are detected only when the disease has progressed to cardiac failure. Screening can detect cases earlier, but there are no screening guidelines.

METHODS

We performed a cross-sectional screening study in Tonga among 5,053 primary school children, in whom auscultation followed by echocardiography of those with heart murmurs were used to identify RHD. We also analyzed whether a three-stage screening protocol of auscultation performed by a medical student to detect any heart murmur, second-stage auscultation performed by a local pediatrician to differentiate pathological from innocent murmurs and echocardiography of those with pathological murmurs altered outcomes.

RESULTS

The prevalence of definite RHD was 33.2 per 1,000. The prevalence of RHD increased significantly with age, peaking at 42.6 per 1,000 in children aged 10-12 years. Most valve lesions (91 [54%] of 169) were mild. Auscultation to detect pathological murmurs was poorly sensitive (46.4%), and the finding of any murmur on auscultation did not affect the likelihood of detecting pathology on echocardiography. The finding of a pathological murmur did significantly increase the likelihood of detecting pathology on echocardiography, but still missed 54% of those with pathology (mainly RHD) detected on echocardiography.

CONCLUSIONS

Screening is a useful method for detecting asymptomatic RHD in regions of high prevalence and we report a high echocardiographically confirmed prevalence. The most appropriate screening strategy remains to be confirmed, however, and implementation will depend on the availability of echocardiography and trained staff.

A Pilot Study of the Clinical Impact of Hand-Carried Cardiac Ultrasound in the Medical Clinic

BACKGROUND

Small, hand-carried ultrasound devices have become widely available, making point-of-care echocardiograms (echos) accessible to all medical personnel as a means to augment and improve the increasingly inefficient physical examination. This study was designed to determine the clinical utility of hand-carried echo by medical residents in clinical decision making.

METHODS

Nine residents underwent brief, practical echo training to perform and interpret a limited hand-carried echo as an integral component of their office examination. The residents' hand-carried echo consisting of four basic views to define left ventricular (LV) function and wall thickness, valvular disease, and any pericardial effusions was compared to one performed by a level III echocardiographer.

RESULTS

Seventy-two consecutive medical clinic patients were enrolled with an average image acquisition time of 4.45 minutes. Residents obtained diagnostic images in 94% of the cases and interpreted them correctly 93% of the time. They correctly identified 92% of the major echo findings and 78% of the minor findings. Their diagnosis of LV dysfunction, valvular disease, and LV hypertrophy improved by 19%, 39%, and 14% with hand-carried echo compared to history and physical alone. Management decisions were reinforced in 76% and changed in 40% of patients with the use of hand-carried echo.

CONCLUSION

This study demonstrates that it is possible to train medical residents to perform an effective and reasonably accurate hand-carried echo during their physical examination, which can impact clinical management.

Use of hand-carried ultrasound devices to augment the accuracy of medical student bedside cardiac diagnoses

BACKGROUND

Hand-carried ultrasound (HCU) devices used by cardiologists as extensions of the physical examination have been shown to improve the accuracy of bedside diagnoses. We tested the feasibility of teaching medical students to use HCU devices to make bedside cardiac diagnoses and compared the accuracy of their HCU and physical examinations.

METHODS

In all, 10 fourth-year medical students enrolled in a 4-week medical school course on the cardiac examination. Students examined 12 standardized patients at 3 different time intervals: (1) on day 1 of the course; (2) on day 10 after review of cardiac physical examination using traditional teaching methods; and (3) after instruction on the use of HCU devices. Students were scored at each time interval for primary findings (most salient) and all findings, accounting for both errors of commission and omission. Scores could range from +12 to -12 for primary findings and from +22 to -22 for all findings. A perfect score was +12 for primary findings and +22 for all findings.

RESULTS

The average score for all students at baseline was -3.2 +/- 3.1 and -5.7 +/- 4.8 for primary and all findings, respectively. A significant improvement in the scores was noted with use of the HCU device (2.6 +/- 3.1 and 5.2 +/- 6.6 for primary and all findings, respectively) compared with the baseline and two subsequent physical examinations.

CONCLUSION

Instruction of fourth-year medical students on the use of HCU device is feasible and results in significantly more accurate bedside diagnoses.

Comparison of Positive Cases for B-type Natriuretic Peptide and ECG Testing for Identification of Precursor Forms of Heart Failure in an Elderly Population

Plasma B-type natriuretic peptide (BNP) levels have been reported to be elevated in various types of cardiac disorders and in precursors of CHF. To elucidate the potential ability of BNP testing to identify individuals with structural cardiac disease (ie, hypertensive heart disease, coronary heart disease, valvular heart disease) among community-dwelling elderly persons, cases which were positive on BNP testing were compared to those positive on ECG testing. In the initial phase, we performed plasma BNP measurements and ECG in 856 participants (age > or = 65 years) selected from a general population. From within this group, subjects with an abnormal ECG (n = 125) were selected according to the Minnesota code. Subjects with elevated BNP were selected independently on the basis of plasma levels (n = 112). In the next phase, subjects in both groups were invited to complete Rose's angina questionnaire and to undergo physical examination and transthoracic echocardiography. In this subject group (positive in ECG testing and/or BNP testing), the two tests had comparable sensitivity (65% versus 59%: NS) and specificity (40% versus 41%: NS) for identifying hypertensive heart disease (n = 17). For coronary heart disease (n = 12), the two tests had also comparable sensitivity (58% versus 42%: NS) and specificity (39% versus 41%: NS). However, for selection of valvular heart disease (n = 7), BNP testing had higher sensitivity than ECG testing (100% versus 14%; P < 0.01) with comparable specificity (43% versus 40%: NS). Several types of structural heart disease, in particular valvular heart disease, could be identified exclusively by BNP testing, suggesting that BNP measurement can make a significant contribution to screening for CHF precursors when used in combination with ECG in elderly populations.

Clinical Evaluation Versus Echocardiography in the Assessment of Rheumatic Heart Disease

BACKGROUND

Rheumatic heart disease (RHD) is still a common form of heart disease among children and young adults, especially in developing countries like India. Between 1940 and 1983, the prevalence rate of RHD varied from 1.8 to 11 per 1000 (national average 6 per 1000), while between 1984 and 1995 the rate varied from 1 to 5.4 per 1000 [1]. The study was carried out to assess the accuracy of a medical student's clinical evaluation of valvular heart disease and compare it with that of an echocardiographic evaluation and to determine the sensitivity, specificity and predictive values of clinical examination as compared to echocardiography for the various lesions in RHD patients.

METHOD

50 children between the ages of 5-16 years, attending the out patient department or admitted in a large teaching hospital, satisfying the criteria of RHD, were included in the study. Each patient underwent detailed clinical evaluation and relevant investigations including echocardiography.

RESULTS

Mitral valve was involved most often both by echocardiography and clinically. Isolated aortic valve involvement was rare. The most common lesion was mitral regurgitation (MR) both by auscultation and by echo. Mixed lesions were seen more often than pure lesions. Mitral stenosis (MS) had the highest sensitivity while tricuspid regurgitation (TR) had the highest specificity. MR had the highest positive predictive value and MS the highest negative predictive value. Sensitivity and specificity of aortic regurgitation (AR) was very low when compared to earlier studies. There was a statistically significant difference between echo diagnosis and clinical diagnosis (p < 0.05).

CONCLUSION

It is recommended that echocardiography be done routinely for the diagnosis of cardiac lesions in patients of RHD as clinical examination alone can miss various lesions, especially when the lesions are mild or when multiple lesions are present.

Unsuspected clinically important findings detected with a small portable ultrasound device in patients admitted to a general medicine service

OBJECTIVE

We sought to determine whether physicians with training in echocardiography could successfully use a small echocardiographic device to detect occult cardiovascular disease in patients admitted to a general medical service.

METHODS

In all, 103 consecutive patients had a physician-performed bedside echocardiographic examination with a small portable ultrasound device.

RESULTS

Of patients, 70% did not have a clinical indication for echocardiography and of these patients, 39% had an abnormal study with the portable ultrasound device. There was a high rate of false-positive examinations, but approximately 17% of patients without a clinical indication for echocardiography had an important cardiac abnormality detected, including 10% with unsuspected left ventricular systolic dysfunction.

CONCLUSIONS

Many patients on a general medical hospital ward have unsuspected, clinically important cardiac findings such as left ventricular dysfunction that can be screened for by physicians with training in echocardiography using small portable ultrasound devices.

Role of history and physical examination in preoperative evaluation

BACKGROUND AND OBJECTIVE

Since reports have shown that outpatient preoperative evaluation increases the quality of care and cost-effectiveness, an increasing number of patients are being evaluated purely on an outpatient basis. To improve cost-effectiveness, it would be appealing if those patients who are healthy and ready for surgery without additional testing could be easily distinguished from those who require more extensive evaluation. This paper examines whether published studies provide sufficient data to determine how detailed preoperative history taking and physical examination need to be in order to assess the health of surgical patients and to meet the objective of easy and early distinction.

METHODS

A MEDLINE search was conducted from 1991 to 2000 with respect to preoperative patient history and physical examination. Altogether, 213 articles were found, of which 29 were selected. Additionally, 38 cross-references, 7 articles on additional testing and 4 recently published papers were used.

RESULTS

It is questionable to what extent an extensive history is relevant for anaesthesia and long-term prognosis. With respect to physical examination, it seems unreasonable to diagnose valvular heart disease based on cardiac auscultation only, and it is unclear which method should be used to predict the difficulty of endotracheal intubation. The benefits of routine testing for all surgical patients before operation are extremely limited and are not advocated.

CONCLUSIONS

The amount of detail of preoperative patient history and the value of physical examination to obtain a reasonable estimate of perioperative risk remains unclear. Although not evidence based, a thorough history taking and physical examination of all patients before surgery seems important until more evidence-based guidelines become available. Diagnostic and prognostic prediction studies may provide this necessary evidence.

The hand-carried echocardiographic device as an aid to the physical examination

Physical examination skills have been declining over the past several decades while technology has made diagnostic testing increasingly sophisticated. For patients with cardiovascular disease, the best approach to bedside diagnosis would be one that combines both physical examination and ready access to technology at the time of the patient encounter. Most cardiac testing is not performed at the bedside due to equipment size and time limitations for these tests. Small hand-carried echocardiographic devices are now available for rapid bedside examination. These devices compare well to full-featured systems when used in cardiology outpatient settings and in hospitalized patients who are not critically ill. Compared with physical examination by board certified cardiologists, these devices decrease diagnostic error. Early use of hand-carried echocardiographic devices after physical examination has been demonstrated to impact patient triage and treatment as well as uncover otherwise undetected cardiac disease. The degree of training required for responsible use of these devices is as yet unclear. However, organized training sessions have resulted in modest agreement with standard echocardiography and point-of-care echocardiography performed by expert echocardiographers. It is conceivable that the hand-carried echocardiographic devices will be used in medical school curriculum to enhance medical student education in the future.

[Comparison of echocardiographic studies made with new portable devices to conventional studies]

OBJECTIVES

The latest development in echocardiography is the hand-held ultrasound device. Previous studies have shown that portable ultrasound devices detect major cardiovascular pathology better than the physical examination, but their diagnostic accuracy is still not known. The purpose of this study was to compare the results of examinations made with portable devices to those obtained with higher-scale platforms.

PATIENTS AND METHOD

211 consecutive unselected patients were included in the study. Patients were randomly studied with a portable device and a standard platform (considered the gold standard for comparison) by cardiologists experienced in echocardiography. Parameters of cardiac morphology and function, and valvular regurgitation were compared and analyzed using the McNemar paired test. Differences of more than one grade were considered major differences.

RESULTS

The subjective assessment of the studies made with the portable device was significantly worse. The correlation between estimates of left ventricular function (differences not statistically significant) was adequate, but significant differences were detected in the evaluation of left atrial enlargement, left ventricular hypertrophy, aortic root enlargement, and mitral and tricuspid regurgitation.

CONCLUSIONS

Hand-held cardiac ultrasound devices do not satisfy criteria for a complete echocardiographic study. They provide accurate information about ventricular function but fail to adequately measure cardiac chambers or assess valve function.

Determinants and assessment of regurgitation after mitral valve repair

OBJECTIVES

The ability to detect residual regurgitation is important in the management of patients after mitral valve repair. We performed a study of 264 patients to determine the risk factors and to compare the accuracy of clinical assessment with that of echocardiography.

METHODS

Operative details and valve pathologic data were obtained from individual patient case notes. Clinical assessment consisted of history, examination, and electrocardiography. The presence of regurgitation was ranked in 7 grades, from none to severe. Transthoracic echocardiography was performed blinded to and independently of clinical assessment on the same visit and was graded similarly. Univariate analyses of demographic, etiologic, and operative variables were performed. Significant factors were entered into a multivariate logistic regression model. Sensitivities and specificities were calculated for each diagnostic modality, and the kappa statistic was used to express agreement.

RESULTS

Mean (+/- SE) freedoms from regurgitation at 1 and 5 years were 91.5% +/- 1.7% and 47.5% +/- 3.2%. Factors independently associated with postoperative regurgitation were poor ventricular function (P =.04), increased age (P =.01), and chordal procedures (P =.006). When assessing the presence of regurgitation, auscultation conferred a specificity of 78%, a sensitivity of 77%, and a kappa of 0.43 relative to echocardiography. Electrocardiographic criteria for left ventricular hypertrophy were superior, with a complete specificity of 100% but a low sensitivity of 15%. Agreement within 7 grades of severity was moderate, with a weighted kappa value of 0.42.

CONCLUSIONS

The hazard function for regurgitation after mitral repair increases steadily after the third year, with ventricular function, age and chordal procedures as independent risks. Clinical assessment and electrocardiography are excellent in identifying regurgitation, but their agreement is less when grading severity.

Prognostic value of low-dose dobutamine echocardiography in patients with idiopathic dilated cardiomyopathy

STUDY OBJECTIVES

Dobutamine echocardiography is widely used for the evaluation of myocardial contractile reserve. The purpose of the study was to determine the prognostic value of low-dose dobutamine echocardiography in patients with idiopathic dilated cardiomyopathy (IDCM).

PATIENTS

The study group consisted of 77 consecutive patients with recently diagnosed IDCM (mean [+/- SD] age, 49 +/- 9 years; men, 82%) and left ventricular (LV) ejection fractions of < 40%.

INTERVENTIONS

Two-dimensional and Doppler echocardiographic variables were measured before and after the infusion of dobutamine at the rate of 10 microg/kg/min for 5 min.

MEASUREMENTS AND RESULTS

During a mean follow-up period of 63 +/- 7 months (range, 49 to 75 months) 30 patients (39%) died and five patients (6%) underwent successful heart transplantations. Using multivariate regression analysis, the only significant factors related to fatal outcome or the need for cardiac transplantation were the following: (1) LV end-systolic volume of > 150 mL after low-dose dobutamine infusion (odds ratio [OR], 2.2; confidence interval [CI], 1.2 to 4.1; p = 0.011); (2) no decrease of LV end-diastolic volume after dobutamine infusion (OR, 1.9; CI, 1.1 to 3.4; p = 0.031); (3) atrial fibrillation (OR, 2.7; CI, 1.4 to 5.3; p = 0.003); and (4) male gender (OR, 2.6; CI, 1.2 to 5.5; p = 0.017). A scoring system was proposed with one point assigned for each of the above-mentioned factors. The mortality rates for total scores of 0, 1, 2, 3, and 4 were 0%, 19%, 48%, 83%, and 100%, respectively.

CONCLUSION

The response of the LV to low-dose dobutamine infusion adds clinically valuable prognostic information to the evaluation of the patient with IDCM.

Physician-performed point-of-care echocardiography using a laptop platform compared with physical examination in the cardiovascular patient

OBJECTIVES

The purpose of this study was to compare the results of physical examinations (PEs) performed by board-certified cardiologists with the results of point-of-care (POC) echocardiography in a group of patients with cardiovascular disease.

BACKGROUND

Although cardiovascular PE is crucial in the evaluation of patients with suspected heart disease, the skills required to diagnose abnormal cardiovascular findings have been declining. Echocardiography is a powerful noninvasive cardiovascular diagnostic tool; however, echocardiographic evaluation of patients is not performed at the time of patient encounter (POC echocardiography), beacuse current platforms are cumbersome and expensive for individual physician use. The development of miniaturized echocardiographic equipment has the potential to overcome some of these limitations.

METHODS

Thirty-six subjects had a complete cardiovascular examination by four board-certified cardiologists. The physicians subsequently imaged each patient using a miniaturized echocardiographic platform. The yield of PE and POC echocardiography were compared using a complete echocardiographic study as the gold standard, performed on an upper-end platform.

RESULTS

Cardiac examination failed to detect 59% of the overall cardiovascular findings. Physician-performed echocardiography with the prototype device missed 29% of the overall cardiovascular pathology. When considering only the major cardiovascular findings, the cardiologists' PEs still failed to correctly detect 43%. Point-of-care echocardiography reduced this to 21% without significant interphysician variation.

CONCLUSIONS

Point-of-care echocardiography using a miniaturized echocardiographic platform substantially improved the detection of important cardiovascular pathology compared with PE. Use of this device by a cardiovascular specialist with training in echocardiography as a routine adjunct to PE appears to be useful.

Prevalence and diagnostic value of precordial murmurs for valvular regurgitation in obese patients treated with dexfenfluramine

Echocardiography is recommended for the detection of valvular regurgitation in asymptomatic users of anorexigens with a heart murmur. To determine the prevalence and diagnostic value of heart murmurs for valvular regurgitation, 223 patients receiving dexfenfluramine therapy for 6.9 months and 189 matched controls underwent history and cardiac auscultation by experienced noncardiologists unaware of echocardiography. Color Doppler echocardiograms were interpreted by 3 observers unaware of patients' clinical data. The frequency of at least mild regurgitation of any valve and abnormal regurgitation (moderate mitral or tricuspid or mild aortic regurgitation) were determined. Heart murmurs heard in 31 dexfenfluramine users (14%) and in 20 controls (11%) were all systolic and of grade I to II/VI intensity. Mild or worse regurgitation of any valve showed a trend in patients (18% vs 11.6% in controls, odds ratio [OR] 1.66, confidence interval [CI] 0.95 to 2.9, p = 0.08), but abnormal regurgitation (includes Food and Drug Administration grade regurgitation) was more common in patients (9% vs 3% in controls, OR 3.0, CI 1.18 to 7.65, p = 0.02). In dexfenfluramine users, heart murmurs were associated with at least mild or abnormal regurgitation (OR 3.1 and 3.05, 95% CI 1.34 to 7.13 and 1.1 to 8.67; p = 0.008 and 0.036, respectively), had a specificity of 89% and 88%, negative predictive value of 85% and 93%, but sensitivity of 37% and 30%, and positive predictive value of 35% and 19%, respectively. Most valves missed by cardiac auscultation had normal morphology and mild regurgitation. Finally, heart murmurs had better diagnostic value for either type of valvular regurgitation than heart murmurs and clinical variables or clinical variables alone. In summary, in dexfenfluramine users the prevalence of heart murmurs was low and their absence predicted absence of mild or worse regurgitation of any valve or abnormal valvular regurgitation. Therefore, cardiac auscultation should be the screening method of choice for detecting valvular regurgitation in users of anorexigens.

Diagnosis of rheumatic fever: current status of Jones Criteria and role of echocardiography

The original Jones Criteria as proposed by Dr. T. Duckett Jones have been modified four times and the updated revised criteria were published in 1992. According to this latest publication major manifestations are carditis, polyarthritis, chorea, erythema marginatum and subcutaneous nodules. Minor manifestations include fever, arthralgia and laboratory findings of elevated erythrocyte sedimentation rate, C-reactive protein and prolonged PR interval on ECG. For making a diagnosis of acute rheumatic fever, two major, or one major and two minor manifestations must be accompanied by supporting evidence of antecedent group A streptococcal infection in the form of positive throat culture or elevated or rising anti-streptolysin titre. The updated guidelines also highlighted a subgroup of "exceptions to Jones Criteria" for patients with chorea, indolent carditis and previous history of rheumatic fever or "rheumatic heart disease". Role of echocardiography has not been defined in these modifications but may be important, as clinical detection of soft murmurs may be difficult due to tachycardia. Doppler and color flow mapping is more sensitive in picking up minor digress of valvular regurgitation. Several studies have confirmed that the yield of carditis with valvular regurgitation increased with use of echocardiography in patients with acute rheumatic fever. Also echocardiography is of great help in mixed valve lesions to determine the severity of each lesion. Other abnormalities detected on echocardiography in acute carditis include prolapse of the valve, focal nodular thickening of leaflets and pericardial effusion. Jones Criteria are guidelines to assist the physician and should not be substituted for clinical judgement as strictly following them may result in underdiagnosis of this disease in our country.

Physical examination in valvular aortic stenosis: correlation with stenosis severity and prediction of clinical outcome

BACKGROUND AND METHODS

The goal of this study was to examine the ability of physical examination to predict valvular aortic stenosis severity and clinical outcome in 123 initially asymptomatic subjects (mean age 63 +/- 16 years, 70% men) followed up for a mean of 2.5 +/- 1.4 years.

RESULTS

Doppler aortic jet velocity correlated with systolic murmur intensity (P =.003) and timing (P =.0002), a single second heart sound (P =.01), and carotid upstroke delay (P <.0001) and amplitude (P <.0001). However, no physical examination findings had both a high sensitivity and a high specificity for the diagnosis of severe valvular obstruction. Clinical end points were reached in 56 subjects (46%), including 8 deaths and 48 valve replacements for symptom onset. Univariate predictors of outcome included carotid upstroke delay (P =.0008) and amplitude (P =.0006), systolic murmur grade (P <.0001) and peak (P =.0003), and a single second heart sound (P =.003). On multivariate Cox regression analysis, the only physical examination predictor of outcome was carotid upstroke amplitude (P =.0001).

CONCLUSIONS

Although physical examination findings correlate with stenosis severity, echocardiography still is needed to exclude severe obstruction reliably when this diagnosis is suspected.

Aortic stenosis. Clinical evaluation and optimal timing of surgery

Aortic valve disease is common in the elderly with recent data suggesting that aortic sclerosis and stenosis are the end-stage of an active disease process. Aortic atenosis may be diagnosed at symptom onset (angina, heart failure or syncope) but often the diagnosis is suspected in an asymptomatic patient with a systolic murmur. The diagnosis can be confirmed and disease severity evaluated reliably using Doppler echocardiography. Symptomatic severe aortic stenosis is treated with valve replacement, even in the elderly, due to the extremely poor prognosis without relief of outflow obstruction. Management is controversial when there is coexisting moderate aortic stenosis and left ventricular systolic dysfunction.

Comparative value of Doppler echocardiography and cardiac catheterization in the decision to operate on patients with aortic stenosis

With the use of Doppler echocardiography, severity of valvular stenosis, etiology and type of valve lesions, and left ventricular function can be assessed accurately in patients with aortic stenosis. The purpose of this study was to compare the value of noninvasive clinical and Doppler echocardiographic findings, with cardiac catheterization, in the management decision-making for patients with aortic stenosis. One hundred and seventy consecutive patients with aortic stenosis who underwent cardiac catheterization and Doppler echocardiography were prospectively studied. A decision to operate, not operate or remain uncertain was made independently by experienced cardiologists given clinical information in combination with either Doppler echocardiographic (group I) or cardiac catheterization (group II) data. The severity of aortic stenosis agreed between Doppler echocardiography and cardiac catheterization in 168 patients (98.8%), and disagreed in two patients. There was agreement on clinical decision to operate or not operate between Group I and Group II in 160 patients (94.1%) and a discrepant decision in only two patients (1.1%). In eight patients (4.7%) with poor echogenecity or with discordance between clinical and echocardiographic data, the decision made by group I remained uncertain. We conclude that in a large majority of patients with aortic stenosis, Doppler echocardiographic assessment provides the same management decision reached by cardiac catheterization findings.

Use of transesophageal echocardiography to predict significant coronary artery disease in aortic stenosis

STUDY OBJECTIVES

This study was conducted to examine if the use of multiplane transesophageal echocardiography (TEE) could predict the absence or the presence of significant coronary artery disease (CAD) in patients with aortic stenosis.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENTS

Clinical, angiographic features and TEE findings were prospectively analyzed in 132 consecutive patients with aortic stenosis.

MEASUREMENTS AND RESULTS

In 63 patients with significant CAD, 57 had thoracic aortic plaque on TEE studies. In contrast, aortic plaque existed in only 19 of the remaining 69 patients with normal or mildly abnormal coronary arteries. Therefore, the presence of aortic plaque on the TEE identified significant CAD with a sensitivity of 90.5%, a specificity of 72.5%, and with positive and negative predictive values of 75.0% and 89.3%, respectively. There was a significant relation between the severity of thoracic aortic atherosclerosis and the severity of CAD (p<0.0001). Multivariate logistic regression analysis revealed that aortic plaque, angina, and age were independent predictors of CAD. Aortic plaque was the most significant independent predictor.

CONCLUSION

This prospective study indicates that TEE examination of thoracic atherosclerotic plaque is a powerful predictor of absence of significant CAD in patients with aortic stenosis.

Time-related trends in the preoperative evaluation of patients with valvular stenosis

To investigate time-related trends in the use of preoperative invasive hemodynamics in patients with pure valvular stenosis, the preoperative evaluations and preoperative echocardiograms of consecutive patients who underwent aortic or mitral valve surgery from 1986 to 1994 at the Cleveland Clinic Foundation were reviewed. The study group consisted of 1,985 patients, 1,476 with aortic stenosis and 509 with mitral stenosis. Preoperative cardiac catheterization was performed in 1,456 patients with aortic stenosis (99%) and 488 with mitral stenosis (96%). Measurement of invasive hemodynamics (including transvalvular gradients and estimated valve areas) during catheterization decreased over time both in patients with aortic (from 64% in 1986 to 30% in 1994, test for trend p <0.0001) and mitral stenosis (from 63% in 1986 to 18% in 1994, test for trend p <0.0001). After adjusting for age, gender, and other characteristics, the only predictors of performance of invasive hemodynamics in patients with aortic stenosis were more recent surgery (inverse relation, p = 0.0001) and New York Heart Association class (p = 0.01); in patients with mitral stenosis the only predictor was also more recent surgery (inverse relation, p = 0.0001). Thus, use of preoperative invasive hemodynamics in patients with valvular stenosis has markedly decreased over the last decade. This is an example of how a noninvasive modality can supercede an invasive one, even when surrounding a procedure as fundamentally invasive as valvular heart surgery.

Severely symptomatic mitral stenosis with a low gradient: a case for low-technology medicine

We have observed a group of patients with mitral valve disease and severe symptoms but also with low transmitral gradients and normal cardiac outputs who defy the traditional hemodynamic explanation of mitral stenosis. We performed a 10-year retrospective chart review of all mitral valve replacements at our institution to further characterize this population. The study group consisted of 16 of 132 patients (12%) with symptomatically severe (New York Heart Association [NYHA] class 3.3 +/- 0.5) mitral stenosis but a low (< 10 mm Hg) transmitral gradient, a normal cardiac output (4.8 +/- 1.2 L/min), and a preserved valve area (1.6 +/- 0.4 cm2). Sixteen patients were randomly chosen from the remaining group to serve as a comparison population. Study patients were noted to have less atrial fibrillation, lower wedge and mean pulmonary artery pressures, and a higher incidence of subvalvular disease identified at the time of surgery than did the comparison population. Left ventricular end-diastolic pressure and cardiac output did not differ. Study patients did well with surgery and reported an excellent functional benefit. We believe that this subgroup of patients with mitral valve disease is important, may be missed by using conventional criteria of valve area to determine timing of surgical intervention, and may have their symptoms primarily because of subvalvular disease. Further and perhaps most important, this group illustrates the ongoing need for careful clinical assessment skills and judgement in the face of ever-increasing technology.

Value of the cardiovascular physical examination for detecting valvular heart disease in asymptomatic subjects

To determine the accuracy of the cardiovascular physical examination for the diagnosis of asymptomatic valvular heart disease (VHD), we prospectively studied 143 subjects, 68 apparent normal subjects and 75 patients with diseases known to produce VHD. All subjects underwent a complete physical examination with dynamic cardiac auscultation by a physician blinded to clinical data and compared with the results of transesophageal color Doppler echocardiography (TEE). By TEE, 33 subjects (23%), and by physical examination, 25 subjects (17%) had at least 1 form of VHD. Despite a high frequency of mild valve abnormalities and a 31% prevalence of functional murmurs, the physical examination showed a sensitivity of 70%, a specificity of 98% (confidence interval = 0.51 to 0.84, and 0.94 to 0.99, respectively), and a positive and negative predictive value of 92% for the diagnosis of VHD. Only 2 of the 10 patients with VHD by TEE, but not by physical examination, had clinically important VHD. We conclude that the physical examination is a sensitive and highly specific method of screening for VHD in subjects without cardiac symptoms. Therefore, its use should be encouraged rather than the routine application of echocardiography.

Intensity of murmurs correlates with severity of valvular regurgitation

PURPOSE

To evaluate the relationship between the intensity of murmurs and severity of mitral and aortic regurgitation.

PATIENTS AND METHODS

Consecutive patients with chronic isolated aortic (n = 40) or mitral (n = 170) regurgitation undergoing echocardiographic quantitation of regurgitation between 1990 and 1991 were studied. Regurgitant volume and fraction were measured using two simultaneous methods (quantitative Doppler echocardiography and quantitative two-dimensional echocardiography); the intensity of the regurgitant murmur (grade 0 to 6) was noted by physicians unaware of the study.

RESULTS

Correlations between murmur intensity and regurgitant volume and fraction were good in aortic regurgitation (r = .60 and r = .67, respectively; P < 0.001) and mitral regurgitation (r = .64 and r = .67, respectively; P < 0.001) but weaker (r = .47 and r = .45, respectively) in the subset of mitral regurgitation of ischemic or functional cause. Murmur intensity grades > or = 3 for aortic regurgitation and > or = 4 for mitral regurgitation predicted severe regurgitation (regurgitant fraction > or = 40%) in 71% and 91% of patients, respectively. Murmur grades < or = 1 for aortic regurgitation and < or = 2 for mitral regurgitation predicted "not severe" regurgitation in 100% and 88% of patients, respectively. Murmur grades 2 for aortic regurgitation and 3 for mitral regurgitation were not correlated to degree of regurgitation. The severity of regurgitation was the most powerful determinant of intensity of murmur.

CONCLUSIONS

Murmur intensity correlates well with the degree of chronic organic aortic and mitral regurgitation, and can be used as a predictor of regurgitation severity and as a simple guideline for diagnostic testing in these patients.

Missed diagnosis of severe symptomatic aortic stenosis

Patients with angina pectoris and congestive heart failure with a systolic murmur should be suspected of having significant AS. These patients are frequently women with atrial fibrillation and no left ventricular hypertrophy criteria on the electrocardiogram. Echocardiography with calculation of the aortic valve area is indicated in all these patients.

Aortic regurgitation in coronary artery bypass grafting: implications for cardioplegia administration

BACKGROUND

Echocardiography can detect aortic regurgitation (AR) that may interfere with the adequate delivery of cardioplegia solution to the myocardium during cardiac operation. When aware of this lesion, the surgeon can modify the operative technique accordingly. We sought to evaluate the ability of intraoperative transesophageal echocardiography to detect AR and to correlate the severity of the lesion with the need for retrograde cardioplegia administration.

METHODS

Eighty-four consecutive patients undergoing coronary artery bypass grafting were evaluated. When AR was noted by intraoperative transesophageal echocardiography, a cannula was placed in the coronary sinus for possible retrograde cardioplegia administration. The surgeon was unaware of the severity of AR. After operation, the severity of AR was quantitated using the ratio of the regurgitation jet width to the left ventricular outflow tract diameter.

RESULTS

The AR patients who required retrograde cardioplegia had a significantly higher ratio of regurgitation jet width to left ventricular outflow tract diameter than those AR patients who did not (0.36 +/- 0.06 versus 0.19 +/- 0.06, p < 0.005).

CONCLUSIONS

Transesophageal echocardiography can provide accurate information regarding the presence and severity of AR. The calculated severity of AR on transesophageal echocardiography is associated with the need for retrograde cardioplegia administration.

Quantification of mitral regurgitation--comparison of the proximal flow convergence method and the jet area method

A total of 92 patients with mitral regurgitation (age 63 +/- 13 years, 51 men, 41 women), quantified by angiography, were studied using color-flow Doppler imaging of isovelocity surface areas in the flow convergence region proximal to the regurgitant orifice (PISAs) and of the regurgitant jet in the left atrium. The PISA radii for the flow velocities (aliasing borders) of 28 and 41 cm/s, jet area, jet length, and relation of jet area to left atrial area were measured. A proximal flow convergence region was imaged in 98% (85%) of all patients for a flow velocity of 28 (41) cm/s. A regurgitant jet could be visualized in all patients. The PISA radii for both flow velocities correlated more closely with the angiographic grade (rSp = 0.79 for both flow velocities) than the jet area (rSp = 0.43), jet length (rSp = 0.39), and relation of jet area to left atrial area (rSp = 0.37). A correct differentiation of grade I-II from grade III-IV mitral regurgitation was provided in 95% of the patients by the proximal flow convergence method for both flow velocities and in up to 78% of the patients by the jet area method using the uncorrected jet area. The PISA radii correlated weakly with the parameters from the regurgitant jet (r = 0.5-0.58). It can be concluded that the proximal flow convergence method and the jet area method reach comparable sensitivity for the detection of mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)