Severe diastolic dysfunction as a clue to the cause of stroke: a case report

Background

The echocardiographic determination of cardiac causes of stroke focuses on the presence of left ventricular thrombus, valvular vegetations, and patent foramen ovale. Transoesophageal echocardiogram (TEE) is indicated when the transthoracic echocardiogram (TTE) is inconclusive or when there is clinical suspicion of cardiac causes that may have been missed by TTE. The presence of severe diastolic dysfunction on TTE in the absence of any other cardiac abnormality or cardiac history is not usually considered a clue to the cause of stroke.

Case summary

This is a case of a 52-year-old woman who presented with a stroke. Transthoracic echocardiogram was inconclusive for source of embolus. Transoesophageal echocardiogram revealed left atrial appendage (LAA) thrombus and severely hypokinetic LAA, despite the patient being in normal sinus rhythm (NSR). Retrospective analysis of diastolic function on the prior TTE revealed severe restrictive diastolic dysfunction with evidence of elevated left ventricular end-diastolic pressure. While technetium pyrophosphate scan was negative, magnetic resonance imaging was consistent with cardiac amyloid and further testing revealed multiple myeloma as the cause of the amyloid light chain amyloidosis. This case highlights the importance of scrutinizing diastolic function in patients with a source of embolus and careful assessment for LAA thrombus on TEE, despite NSR.

Discussion

We present a patient with stroke with inconclusive TTE findings and eventual diagnosis of restrictive cardiomyopathy secondary to cardiac amyloidosis from an undiagnosed multiple myeloma. Severe restrictive diastolic function on TTE may be a clue to the discovery of LAA thrombus on TEE.

Blinded, randomized trial of sonographer versus AI cardiac function assessment

Artificial intelligence (AI) has been developed for echocardiography1-3, although it has not yet been tested with blinding and randomization. Here we designed a blinded, randomized non-inferiority clinical trial (ClinicalTrials.gov ID: NCT05140642; no outside funding) of AI versus sonographer initial assessment of left ventricular ejection fraction (LVEF) to evaluate the impact of AI in the interpretation workflow. The primary end point was the change in the LVEF between initial AI or sonographer assessment and final cardiologist assessment, evaluated by the proportion of studies with substantial change (more than 5% change). From 3,769 echocardiographic studies screened, 274 studies were excluded owing to poor image quality. The proportion of studies substantially changed was 16.8% in the AI group and 27.2% in the sonographer group (difference of -10.4%, 95% confidence interval: -13.2% to -7.7%, P < 0.001 for non-inferiority, P < 0.001 for superiority). The mean absolute difference between final cardiologist assessment and independent previous cardiologist assessment was 6.29% in the AI group and 7.23% in the sonographer group (difference of -0.96%, 95% confidence interval: -1.34% to -0.54%, P < 0.001 for superiority). The AI-guided workflow saved time for both sonographers and cardiologists, and cardiologists were not able to distinguish between the initial assessments by AI versus the sonographer (blinding index of 0.088). For patients undergoing echocardiographic quantification of cardiac function, initial assessment of LVEF by AI was non-inferior to assessment by sonographers.

Dissimilar Atrial Rhythms Seen by Transesophageal Echocardiography During an Electrophysiology Study

Dissimilar atrial rhythms describe the coexistence of atrial fibrillation in one atrium and a more regular rhythm in the other. Electrograms are typically used to diagnose this rare entity. The use of transesophageal echocardiography in this context has not been described previously. We present a case of an 88-year-old woman with paroxysmal atrial fibrillation and new-onset, symptomatic atrial flutter who underwent electrophysiology study that confirmed dissimilar atrial rhythms. Transesophageal echocardiography images reveal differential function of the left and right atrial appendages, a novel finding that may be useful in diagnosing this rhythm disorder.

Left ventricular cavity obliteration: Mechanism of the intracavitary gradient and differentiation from hypertrophic obstructive cardiomyopathy

Background

Controversy surrounds the cause of the pressure gradient in patients with hypertrophic obstructive cardiomyopathy (HOCM). Left ventricular cavity obliteration (LVCO) was first described as the cause of the gradient but subsequently systolic anterior motion (SAM) of the mitral valve has been established as the cause. Nevertheless, the two gradients, though different in origin and significance, share similar characteristics. They both have a similar “dagger” profile, are obtained from the cardiac apex, are associated with a hyperdynamic left ventricle, and the gradients are worsened by Valsalva. The distinction has clinical relevance, because treating the intracavitary gradient (ICG) of LVCO as if it were a SAM‐associated gradient associated with HOCM would be inappropriate and possibly harmful.

Materials and Methods

To clarify the cause and characteristics of the ICG in patients with LVCO in patients without HOCM, we assessed the extent and duration of cavity obliteration, and for differentiation, we compared the spectral profiles with patients with HOCM and severe aortic stenosis (AS).

Results

Higher ICG is associated with a greater extent and more prolonged apposition of LV walls, and smaller left ventricular cavity size.

The spectral profile of patients with AS, HOCM, and LVCO is differentiated by the peak/mean gradient ratios of 2 or less, 2–3, and 3 or greater, respectively, in >90% of patients. Most patients with LVCO without HOCM or severe LVH have an ICG < 36 mm Hg.

Conclusion

The magnitude of ICG is quantitatively associated with the extent and duration of LVCO. Spectral profiles of severe AS, HOCM, and LVCO can be differentiated by the peak/mean gradient ratio.

Medical Management (β Blocker ± Disopyramide) of Left Ventricular Outflow Gradient Secondary to Systolic Anterior Motion of the Mitral Valve After Repair

Systolic anterior motion of the mitral valve (SAM) occurs intraoperatively after mitral valve repair (MVRr) in up to 14% of cases and typically resolves in the operating room with conservative measures. Less commonly SAM may also occur in the early or late postoperative period. The clinical course and optimal management of such cases is poorly defined, but reoperation is common. We describe our experience using disopyramide to successfully treat postoperative SAM refractory to beta blockade. Seven patients were retrospectively identified with mitral valve prolapse who underwent MVRr from 2003 to 2015 and were found during follow-up to have severe SAM with a left ventricular outflow tract (LVOT) gradient not observed intraoperatively. All 7 patients were successfully managed medically. In 5 cases, SAM persisted even after maximization of beta blockade, and the addition of disopyramide led to significant improvement or resolution of SAM, the LVOT gradient, and mitral regurgitation. The postoperative LVOT gradient initially exceeded 30 mm Hg in 6 of 7 patients. In 2 patients, the LVOT gradient exceeded 100 mm Hg, and both were managed medically with disopyramide with complete resolution of SAM. In conclusion, SAM after MVRr typically follows a benign clinical course and can be managed medically in most cases. When an initial treatment strategy of beta blockade is insufficient, the addition of disopyramide can effectively alleviate and terminate this condition and should be considered before reoperation.

Stress Echocardiography in Octogenarians: Transesophageal Atrial Pacing is Accurate, Safe, and Well Tolerated

The feasibility and diagnostic accuracy of transesophageal pacing stress echocardiography for detection of inducible myocardial ischemia were evaluated in 161 patients 80 years of age or older (mean 84 +/- 3.9, range 80-97). The pacing time was 5.5 +/- 2.5 minutes with a total test time of 37 +/- 7 minutes. The mean achieved heart rate was 96 +/- 7% (83%-121%) of maximum predicted with an average rate pressure product of 21,560 +/- 5175 beats/min x mm Hg. There were minor adverse events in 8% of cases and no major complications occurred. Patient acceptance was high. When compared with myocardial single photon emission computed tomography, pacing stress echocardiography had a sensitivity of 89% and a specificity of 93% for the detection of myocardial ischemia, and 91% agreement (kappa = 0.80, P < .001). We demonstrate that pacing stress echocardiography is safe and accurate for detection of myocardial ischemia and, thus, a reliable substitute to exercise and pharmacologic stress testing in octogenarians.

Erectile dysfunction in the cardiac patient: how common and should we treat?

PURPOSE

Risk factors for erectile dysfunction (ED) (hypertension, diabetes, smoking, lipid abnormality) are also risk factors for coronary artery disease. However, most cardiologists do not routinely ask about ED and patients often are reluctant or embarrassed to discuss it. We determined how common ED was in a group of patients with chronic stable coronary artery disease.

MATERIALS AND METHODS

We administered the validated Sexual Health Inventory for Men (SHIM) 5-item questionnaire, based on the International Index of Erectile Function questionnaire, to 76 men with chronic stable coronary artery disease during routine outpatient cardiology visits. Most of these men had not previously discussed ED with their cardiologist.

RESULTS

The mean patient age was 64 years (range 40 to 82). The questionnaire took about 5 minutes to complete. Of the patients 47% were on beta blockers, 92% statins, 28% diuretics. SHIM score was 21 or less in 53 men (70%), which is indicative of ED. Of the patients 75% had some difficulty achieving erections (question 2) and 67% had some difficulty maintaining an erection after penetration (question 3). The questionnaire reflected successful sildenafil treatment in 4 patients (SHIM scores 23 to 25). If these 4 men are included as having had ED then 57 of 76 (75%) had ED or recent history of ED.

CONCLUSIONS

ED is extremely common in men with chronic coronary artery disease (affecting approximately 75%) yet most cardiologists do not ask about it. The SHIM is a useful, quick and inexpensive tool for discussion and diagnosis of ED in this population. Although it is well established that cardiovascular risk factors are associated with erectile dysfunction, once it is present there is mixed information on whether treating the risk factors will treat the ED. Problems appear to be that lifestyle modification in midlife may simply be too late to effect a change, and some antihypertensive and lipid lowering drugs may actually exacerbate ED. Oral therapy for ED, namely the PDE5 inhibitors, is effective and safe in most cardiac and hypertensive patients. Organic nitrates such as nitroglycerin remain a contraindication to the concomitant use of these drugs. Guidelines for treatment of ED in the cardiac patient issued by the American College of Cardiology/American Heart Association and Princeton Guidelines may be useful in the approach to the cardiac patient with ED.

Evidence for stunned myocardium in humans: a 2001 update

This article describes clinical situations in which stunning occurs and updates previous reviews on the topic. Stunning following angioplasty, angina and exercise-induced ischemia, infarction, and after cardiac surgery are described. In addition, newer concepts regarding stunning, including neurogenic stunned myocardium, are discussed. Left atrial stunning following cardioversion is a recently recognized phenomenon with important clinical implications, but differs from the original concept of post-ischemic stunning.

Evaluation of cardiac structures and function in small experimental animals: transthoracic, transesophageal, and intraventricular echocardiography to assess contractile function in rat heart

OBJECTIVES

The efficacy of three different echocardiographic techniques to assess cardiac structures and function in the rat heart was studied.

BACKGROUND

With increasing costs for large animal studies there is need for improved assessment of ventricular function in small animal models.

METHODS

Transthoracic, transesophageal, or intracavitary echocardiography was performed in 138 rats using either a pediatric or an intravascular ultrasound transducer in control, infarcted, and obese rats. Left ventricular dimensions and wall thickness were measured.

RESULTS

Transthoracic echocardiography allows qualitative and quantitative estimation of cardiac dimensions and ventricular function. End-diastolic and end-systolic diameters were 0.53 +/- 0.08 and 0.26 +/- 0.05 cm in controls, 0.63 +/- 0.08 and 0.41 +/- 0.07 cm in infarcted (p < 0.001 vs controls), and 0.66 +/- 0.1 and 0.21 +/- 0.07 cm in obese rats (p < 0.01 vs controls). Fractional shortening was 52 +/- 6% in controls, 36 +/- 5% in infarcted (p < 0.001), and 68 +/- 9% in obese rats (p < 0.001). Wall thickness was increased in obese rats. Transesophageal echocardiography allows a qualitative rather than quantitative assessment. Intracavitary ultrasound enabled visualization of the endocardium. Following coronary occlusion, fractional shortening and ejection fraction were decreased (30.8 +/- 4.5 vs 44.4 +/- 4.7%, p < 0.005, and 46.7 +/- 8.5 vs 63.4 +/- 5.4%, p < 0.005, respectively).

CONCLUSIONS

Transthoracic echocardiography is a non-invasive technique to sufficiently provide information about cardiac structures and function, while transesophageal echocardiography allows rather a qualitative estimation of the rat heart. Intracavitary ultrasound can be used to assess the endocardium, ventricular function, and dimensions in open-chest studies in rats.

A small animal model of non-ischemic cardiomyopathy and its evaluation by transthoracic echocardiography

BACKGROUND

Costs for large animal studies have escalated. Therefore there is a need to develop small animal models of non-ischemic cardiac failure and accurate non-invasive techniques that will allow serial quantitation of left ventricular function.

OBJECTIVES

The purpose of our study was to determine the efficacy and reliability of adriamycin for inducing cardiomyopathy in rats. We hypothesized that high frequency transthoracic 2-dimensional and M-mode echocardiography would allow for serial testing of cardiac function in this small animal model.

METHODS

Adriamycin was administered at a dose of 2.5 mg/kg intravenously once a week for 10 weeks in 54 rats. Transthoracic echocardiography by use of a 7.5 MHz transducer was performed in 19 rats at baseline and additionally at 12 weeks after beginning of adriamycin therapy to measure left ventricular dimensions and calculate fractional shortening.

RESULTS

The mortality rate during the treatment period was 11%, but increased to 52% at 13 weeks. Transthoracic echocardiography provided adequate visualization of left ventricular dimensions and cardiac function in a parasternal short axis view. In follow-up echocardiography, pericardial effusion was detected in 8/19 rats (42%). Compared to baseline, end-diastolic diameters increased from 0.56 +/- 0.06 to 0.64 +/- 0.08 mm (p < 0.001), end-systolic diameters increased from 0.27 +/- 0.03 to 0.42 +/- 0.08 mm (p < 0.001), and fractional shortening decreased from 52.8 +/- 4.0 to 34.3 +/- 7.1% (p < 0.001) at 12 weeks. Electron microscopy in a subset of rats revealed cardiomyocyte degeneration, mitochondrial and sarcoplasmatic reticular edema, numerous intracellular vacuoles and 'onion-ring' shaped mitochondrial cristae, characteristic for adriamycin cardiotoxicity in human patients.

CONCLUSION

Adriamycin at an intravenous dose of 2.5 mg/kg over 10 weeks can be used to create a reliable model of non-ischemic dilated cardiomyopathy with a high success rate. For in-vivo diagnostic purposes, transthoracic echocardiography provides a reliable technique to non-invasively assess cardiac function quantitatively and qualitatively in follow-up studies in rat cardiomyopathy. This small animal model can easily be used for testing new therapeutic strategies in cardiac failure.

Symptomatic and hemodynamic recovery following dobutamine stress echo: benefit of low-dose esmolol administration

OBJECTIVES

We studied the use of esmolol in patients experiencing minor side effects of palpitations, anxiety, nervousness, and tremors associated with dobutamine stress echocardiography.

BACKGROUND

Dobutamine stress echocardiography is frequently used in the assessment of coronary artery disease. Esmolol administration may enhance patient comfort.

METHODS

Sixty consecutive patients who experienced minor side-effects during dobutamine stress echocardiography were given 0.3 mg/kg esmolol intravenously in the recovery period and compared retrospectively to sixty consecutive controls who underwent dobutamine stress echocardiography, who did not receive esmolol, during the same time period. Both groups were matched for age, ejection fraction, and peak dose of dobutamine. Heart rate and blood pressure were assessed during and after dobutamine administration.

RESULTS

Both groups had similar baseline blood pressure (mmHg) (142 +/- 19/72 +/- 14 vs 139 +/- 20/72 +/- 14) and heart rate (beats per minute) (75 +/- 14 vs 75 +/- 17) (esmolol and control respectively, p = ns), but peak heart rate was higher in the esmolol group (126 +/- 14 vs. 116 +/- 14, p < 0.01). In the group who received esmolol, symptomatic relief paralleled the statistically significant decrease in heart rate which occurred within 1 minute of esmolol administration (99.7 +/- 15.3 vs 108.5 +/- 13.1 p < 0.0001); the heart rate in the esmolol group remained significantly lower than the control group for 5 minutes following esmolol administration (92.0 +/- 10.3 vs 96.7 +/- 11.8 p < 0.05). As a percentage of peak heart rate the esmolol group remained significantly lower than the control for 7 minutes (74% vs 80% p < 0.05). Esmolol induced a significant reversal of dobutamine-induced diastolic hypotension (diastolic blood pressure at peak 66 +/- 17 vs 8 min recovery 70 +/- 12, p < 0.03) that was not seen in controls (diastolic blood pressure at peak 64 +/- 18 vs 8 min recovery 65 +/- 14, p = ns). Systolic blood pressure and heart rate remained elevated in both groups 8 min into recovery compared to baseline, suggesting persistent dobutamine effect beyond the expected 2 min pharmacologic half-life of dobutamine. No side-effects from esmolol were seen despite it being used in 9 patients with EF < 35%.

CONCLUSIONS

Esmolol is effective and well tolerated for the management of dobutamine-related minor side-effects. The mechanism of benefit, in addition to heart rate reduction, may involve a reversal of dobutamine-induced diastolic hypotension. Blood pressure and heart rate recovery are slower than expected from previously published pharmacokinetic data.

Echocardiographic and cardiac Doppler assessment of mice

Recent studies have suggested that intermediate-frequency M-Mode transthoracic echocardiographic imaging is a promising method for evaluating the left ventricle in transgenic mice. However, there is a paucity of data regarding two-dimensional (2-D) echocardiography and cardiac Doppler echocardiography in this model. Therefore we studied 15 mice (body weights 38 to 65 gm) with an ultrasound system equipped with a 9 MHz transducer. M-mode, 2-D, pulsed, and color-flow Doppler studies were performed. Mean +/- SD for septal, posterior wall, and left ventricular cavity dimensions at end diastole were the following: M-mode: 1.1 +/- 0.2, 1.0 +/- 0.2, and 3.7 +/- 0.7 mm; 2-D: 1.0 +/- 0.2, 1.1 +/- 0.3, and 3.0 +/- 0.6mm. Left ventricular fractional shortening was assessed from the M-mode echocardiogram: mean 53.7% +/- 10.7% (range 42% to 77%). 2-D assessment of left ventricular mass correlated better with left ventricular mass identified at necropsy than left ventricular mass identified by M-mode echocardiography (r = 0.70; p = 0.007 versus r = 0.07; p not significant). 2-D visualization of left ventricle, proximal aorta, and aortic and mitral valves was excellent and was obtained mainly from a "parasternal" window. Apical views were more difficult to obtain. Mean +/- SD for aortic peak and mean velocities and velocity-time integral were 0.53 +/- 0.13, 0.32 +/- 0.08, and 0.025 +/- 0.008 m/sec. Estimated stroke volume was 0.0506 +/- 0.018 ml/beat. Cardiac output was 12.64 +/- 7.87 ml/min. Mean +/- SD for mitral peak E, peak A, and E/A ratio were 0.45 +/- 0.09 m/sec, 0.19 +/- 0.06 m/sec, and 2.4 +/- 0.66 m/sec, respectively. In all mice the E/A ratio was greater than 1 (range 1.76 to 3.6). Color-flowing imaging clearly displayed normal mitral inflow and left ventricular outflow. In one mouse, aortic regurgitation was recorded by pulsed Doppler echocardiography. Echocardiographic, pulsed, and color-flow Doppler assessment of mice is feasible. In this study left ventricular mass was assessed better by 2-D measurement of left ventricular dimensions. Assessment of left ventricular performance is feasible. Color Doppler-guided evaluation of aortic flow and aortic root measurement permits assessment of stroke volume and cardiac output.

Femoral vein delivery of contrast medium enhances transthoracic echocardiographic detection of patent foramen ovale

OBJECTIVES

We postulated that femoral vein delivery of contrast medium because of streaming, might enhance precordial echocardiographic detection of patent foramen ovale.

BACKGROUND

Although precordial contrast echocardiography is widely used to diagnose patent foramen ovale, this method is limited by poor sensitivity. Previous investigators have demonstrated enhanced detection of atrial defects by the dye-dilution technique after delivery of contrast medium into the inferior rather than the superior vena cava.

METHODS

Transthoracic contrast examinations were performed in a randomly selected group of 70 patients (without previous history of cerebral or systemic embolus) undergoing cardiac catheterization. Paired contrast agent injections (10 ml dextrose in water/0.25 ml air) were administered from an upper extremity vein and femoral vein in each patient during spontaneous respiration, cough and Valsalva maneuvers. Studies were interpreted by an experienced echocardiographer unaware of the sequence and site of injections. Positive studies were semiquantitatively graded from +1 (minimal left ventricular opacification) to +4 (intense left ventricular opacification). Catheterization and echocardiographic assessment of patent foramen ovale were compared in 21 subjects.

RESULTS

Patent foramen ovale was detected significantly more often during femoral vein versus upper extremity contrast delivery (23 of 70 patients [prevalence 33%] vs. 9 of 70 patients [prevalence 13%], p < 0.001). The intensity of left ventricular opacification was also greater during femoral vein contrast injection. Precordial echocardiography combined with femoral contrast delivery was significantly more sensitive than cardiac catheterization for assessment of patent foramen ovale (8 of 21 patients vs. 2 of 21 patients, p < 0.05).

CONCLUSIONS

Femoral vein contrast delivery significantly enhances the ability of precordial contrast echocardiography to diagnose patent foramen ovale. Physiologic patency of the foramen ovale is more common (prevalence 33%) than previously documented.

The diagnostic utility of contrast echocardiography in patients with refractory hypoxemia

Three illustrative cases of refractory hypoxemia in adults are presented. In two cases contrast echocardiography was invaluable in establishing the diagnosis of a true anatomic right to left shunt, as well as in localizing the shunt to an intracardiac or extracardiac site. In the third case true anatomic right to left shunt was excluded by means of contrast echocardiography. The pathophysiology of hypoxemia is discussed with emphasis on the potential diagnostic utility of contrast echocardiology in patients with refractory hypoxemia. A diagnostic flow chart is proposed.

Coronary artery bypass surgery. Which patients benefit?

Thousands of coronary bypass operations are performed in Canada each year. Some result in longer life or improved quality of life by reducing angina, but others do not. Where the potential benefit is unknown, physicians must consider the patient's work, home life, and personality. Clinical intuition is still needed to determine which patients will benefit.

Dobutamine stress echocardiography: initial experience of a Canadian centre

OBJECTIVE

To investigate the diagnostic accuracy, electrocardiogram and hemodynamic effects and safety of dobutamine stress echocardiography.

SUBJECTS

Sixty-one patients with suspected coronary artery disease. All patients underwent coronary arteriography.

MAIN RESULTS

The sensitivity of dobutamine stress echocardiography in diagnosis of coronary artery disease in the whole group was 91%. In patients with left anterior descending it was 97%; right 85%; circumflex 76%; three vessel 100%; two vessel 95%; single vessel 77%. Specificity, positive predictive value and accuracy of dobutamine stress echocardiography in diagnosis of coronary disease (whole group) was 57, 94 and 87%, respectively. ST depression of more than 1 mm occurred in 11 patients, ST elevation of more than 1 mm in three patients, T wave inversion in one and T normalization in nine. Significant differences of the effects of beta-blockers were noted on the peak effects of dobutamine as follows: heart rate increase of 46 +/- 22 versus 20 +/- 13 beats/min (P less than 0.0001); systolic pressure increase of 4 +/- 26 versus 22 +/- 19 mmHg (P less than 0.01); diastolic pressure decrease of 18 +/- 16 versus 10 +/- 12 mmHg (P less than 0.03) for patients without or with beta-blockers, respectively. Unifocal ventricular premature beats were noted in 10 patients, atrial premature beats in five and ventricular couplets in one. Angina occurred in 11 patients. Atypical chest pain occurred in seven patients, tingling in 11 and nausea in four. Thirty-six patients were totally asymptomatic.

CONCLUSIONS

In this population with high prevalence (85%) of coronary artery disease, dobutamine stress echocardiography had high sensitivity and positive predictive value for coronary disease detection particularly in patients with left anterior descending or three vessel disease. The specificity and accuracy were not as good, but this may reflect the small number of normal patients. Dobutamine was well tolerated and conveniently administered.

Assessment of left atrial appendage function by transesophageal echocardiography. Implications for the development of thrombus

BACKGROUND

The predilection of the left atrial appendage (LAA) for thrombus formation has long been known.

METHODS AND RESULTS

We prospectively studied the two-dimensional echocardiographic and Doppler patterns of LAA function in 82 patients by transesophageal echocardiography. In the 63 patients in sinus rhythm, LAA area was measured during LAA diastole at the onset of the electrocardiographic (ECG) P wave (LAAmax) and after LAA systole at the ECG R wave (LAAmin) and LAA ejection fraction was calculated as (LAAmax-LAAmin)/LAAmax; peak Doppler velocity was recorded from the LAA outlet. The 58 patients in sinus rhythm without LAA thrombus were grouped according to left atrial size on transthoracic echocardiography; 39 patients had a left atrial size of less than 40 mm (group 1) and 19 had a left atrial size of 40 mm or greater (group 2). Five patients in sinus rhythm had LAA thrombus. In the 19 patients with atrial fibrillation or flutter LAAmax was measured independent of the ECG; three of these patients had LAA spontaneous contrast, four had thrombus, and one had both. Patients in sinus rhythm without LAA thrombus demonstrated a characteristic pattern of a contractile LAA apex and a noncontractile base with color flow and pulsed Doppler evidence of LAA emptying that coincided with the P wave. Patients in sinus rhythm with LAA thrombus had a mean +/- SD LAAmax (8.0 +/- 1.5 cm2) larger than that in group 1 (5.0 +/- 1.9 cm2) (p less than 0.01) but not group 2 (6.7 +/- 3.1 cm2), LAAmin (6.5 +/- 1.0 cm2) larger than that in both group 1 (2.3 +/- 1.5 cm2) and group 2 (4.2 +/- 2.7 cm2) (p less than 0.01), and LAA ejection fraction (17 +/- 11%) and LAA velocity (0.24 +/- 0.10 m/sec) less than those in both group 1 (55 +/- 21% and 0.48 +/- 0.24 m/sec, respectively) and group 2 (45 +/- 27% and 0.46 +/- 0.24 m/sec, respectively) (p less than 0.01). Patients with atrial fibrillation or flutter with LAA spontaneous contrast and/or thrombus had LAAmax (10.4 +/- 6.6 cm2) greater than that in patients with atrial fibrillation or flutter without LAA contrast and/or thrombus (6.8 +/- 3.0 cm2) (p less than 0.05). The LAA appeared as a static pouch in seven of eight of the former compared with in two of 11 of the latter. When attempted, Doppler demonstrated a recognizable fibrillatory LAA outflow velocity pattern in none of three in the former versus four of seven in the latter group.

CONCLUSIONS

We conclude that the LAA has a characteristic pattern of emptying in sinus rhythm. LAA thrombus formation in sinus rhythm and atrial fibrillation is associated with both poor LAA contraction and LAA dilation.

Reversible tricuspid regurgitation in a patient undergoing treatment for acute leukemia

A 52-year-old female patient treated for acute lymphoblastic leukemia with combination chemotherapy (cyclophosphamide, vincristine, adriamycin and prednisone), broad spectrum antibiotics and amphotericin via a Hickman catheter placed in the superior vena cava, developed echocardiographically confirmed tricuspid regurgitation. A second admission four months later showed only mild tricuspid regurgitation. The authors conclude that the amphotericin given via the central line caused valvulitis of the tricuspid valve.

Myocardial abscess in a patient with AIDS-related complex: pericardial patch repair

A hemophiliac with acquired immunodeficiency syndrome-related complex was seen with sepsis related to a ventricular septal abscess. The abscess was debrided and the septum was patched with a single layer of autologous pericardium. The patient recovered and survived 6 months before dying of acquired immunodeficiency syndrome. At autopsy, the septal patch was well healed with no evidence of recurrent endocarditis.

Aortic valve replacement with stentless porcine aortic bioprosthesis

Twenty-nine patients were entered in a clinical trial on aortic valve replacement with a stentless glutaraldehyde-fixed porcine aortic valve. This bioprosthesis is secured to the aortic root by the same technique used for aortic valve replacement with aortic valve homografts. The functional results obtained from this operation have been most satisfactory. To assess the hemodynamic benefit of eliminating the stent of a porcine aortic valve, we matched 22 patients with a stentless porcine bioprosthesis for age, sex, body surface area, valve lesion, and bioprosthesis size to 22 patients who had aortic valve replacement with a Hancock II bioprosthesis. Mean and peak systolic gradients across the aortic bioprosthesis and effective aortic valve areas were obtained by Doppler studies. Gradients across the stentless bioprosthesis were significantly lower than gradients across the Hancock II valve for every bioprosthesis size. Effective aortic valve areas of the stentless bioprosthesis were significantly larger than the valve areas of the Hancock II valve. Our data demonstrate that the hemodynamic characteristics of a glutaraldehyde-fixed porcine aortic bioprosthesis are greatly improved when the aortic root is used as a stent for the valve. This technique of implantation is expected to enhance the durability of the bioprosthesis, because the aortic root may dampen the mechanical stress to which the leaflets are subjected during the cardiac cycle.

Transesophageal echocardiography: experience of a Canadian centre

Transesophageal echocardiography (TEE) is a new application of echocardiography in which an ultrasonic transducer is positioned in the esophagus and stomach to obtain images of the heart without interference from lung and bone. It is particularly useful in the assessment of left atrial masses, atrial septal defects, mitral valve disease, valvular prostheses and aortic dissection. In the operative setting, TEE is used to detect early myocardial ischemia in patients with coronary artery disease undergoing noncardiac surgery as well as in the assessment of the results of valvular surgery. This review examines the technique of TEE, its indications and the early experience with the first 100 patients examined at the Toronto Western Hospital with this technique.

Mitral valve annuloplasty: the effect of the type on left ventricular function

This study was undertaken to determine whether rigid-ring annuloplasty and flexible-ring annuloplasty have the same effect on left ventricular function in patients with chronic mitral regurgitation secondary to degenerative disease of the mitral valve. Twenty-five patients who underwent isolated mitral valve repair and required annuloplasty were randomized into two groups: rigid-ring and flexible-ring annuloplasty. Left ventricular function was assessed by echocardiography and radionuclide angiography on the day before operation and 2 to 3 months later. Preoperative left ventricular function was similar in the two groups of patients. Postoperatively, left ventricular end-diastolic diameter and volume decreased significantly in both groups. The left ventricular end-systolic diameter and volume decreased significantly only in patients with a flexible annuloplasty ring. Left ventricular systolic function as assessed by pressure-volume relationships was significantly better in patients with a flexible ring (p less than 0.02 by analysis of covariance), and left ventricular performance measured by stroke volume-end-diastolic volume relationships was also better in these patients (p less than 0.05 by analysis of covariance). These data indicate that patients with a flexible annuloplasty ring have better left ventricular systolic function than patients with a rigid annuloplasty ring 2 to 3 months after mitral valve reconstruction for chronic mitral regurgitation secondary to degenerative disease of the mitral valve.

Acute myocarditis presenting as asymmetric septal hypertrophy

A 19-year-old male with myocarditis presented with the echocardiographic appearance of asymmetric septal hypertrophy. After six days of steroid therapy the septum and the posterior wall returned to normal thickness. This case suggests that a diagnosis of myocarditis should be considered in patients demonstrating asymmetric septal hypertrophy, particularly when there are associated left ventricular wall motion abnormalities.

Disopyramide in hypertrophic cardiomyopathy. I. Hemodynamic assessment after intravenous administration

The hemodynamic effects of intravenous disopyramide were determined in 43 patients with hypertrophic cardiomyopathy and pressure gradients at rest (resting obstruction). The basal subaortic pressure gradient decreased in all patients by a mean of 61 mm Hg (range 16 to 123); in 35 patients the gradient was abolished (less than 20 mm Hg). The reduction in pressure gradient was achieved through a decrease in left ventricular systolic pressure, from 178 to 135 mm Hg (p less than 0.0001), and a rise in aortic systolic pressure, from 105 to 123 mm Hg (p less than 0.0001). Left ventricular ejection time was reduced from 326 to 273 ms (p less than 0.0001). Left ventricular end-diastolic pressure decreased from 19 to 16 mm Hg (p less than 0.0001). In a subgroup of 13 patients, cardiac output was unchanged after disopyramide, despite a prolongation of the pre-ejection period from 104 to 137 ms (p less than 0.0001) indicating a decrease in contractility. The maintenance of cardiac output, despite a decrease in contractility, may reflect a decrease in mitral regurgitation resulting from the reduction of systolic anterior motion of the mitral valve by disopyramide. These results indicate that disopyramide produces predictably favorable hemodynamic effects in patients with hypertrophic cardiomyopathy and resting obstruction to left ventricular outflow.

Disopyramide in hypertrophic cardiomyopathy. II. Noninvasive assessment after oral administration

The effects of oral disopyramide 150 mg 4 times a day were compared with propranolol 40 mg 4 times a day and placebo in 10 patients with hypertrophic cardiomyopathy and resting obstruction (7 patients) or latent obstruction (3 patients), in a randomized double-blind crossover design; each drug was given for a period of 4 days. As determined from echocardiographic evaluation of systolic anterior motion of the mitral valve, the subaortic pressure gradient was decreased from 61 +/- 20 mm Hg with placebo to 5 +/- 15 mm Hg with disopyramide (p less than 0.01), and 30 +/- 30 mm Hg with propranolol (p less than 0.01). Disopyramide was more effective than propranolol (p less than 0.01). Disopyramide and propranolol both shortened left ventricular ejection time from 352 +/- 51 ms with placebo to 314 +/- 26 and 322 +/- 41 ms, respectively (p less than 0.01). Preejection period was lengthened from 93 +/- 35 ms with placebo to 119 +/- 25 ms with disopyramide, but was unchanged by propranolol at 98 +/- 23 ms. Disopyramide increased exercise duration versus placebo (10.4 +/- 2 vs 9.6 +/- 2 minutes, respectively (p less than 0.05), whereas propranolol produced no significant change (8.8 +/- 2 minutes).

Isolated thickening of one aortic cusp: preferential thickening of the noncoronary cusp

Over a 2-year period we identified 197 patients with the previously undescribed finding of isolated thickening of one aortic cusp. The noncoronary cusp was involved most frequently in 56% (p less than 0.01), followed by the right coronary cusp in 35%, and the left coronary cusp in 9%. Isolated thickening of one aortic cusp occurs more commonly in male patients (64%) (p less than 0.01) and at an earlier age (65 years) than mitral annular calcification (70 years) (p less than 0.001).

Colour flow imaging in severe mitral and aortic regurgitation

Several criteria have been proposed for the grading of severe aortic and mitral regurgitation by colour flow imaging. To evaluate the sensitivity of these criteria, colour flow imaging was performed in 21 patients with isolated severe mitral regurgitation and 11 patients with isolated severe aortic regurgitation prior to clinically indicated valvular surgery. In the colour flow imaging assessment of mitral regurgitation the criterion of the maximum distance of mitral regurgitant jet from mitral orifice greater than 4.5 cm was 95% sensitive (range 4.4 to 8.4 cm). Maximum ratio of mitral regurgitant jet area to left atrial area greater than 40% was 86% sensitive (range 32 to 84%) and maximum mitral regurgitant jet area greater than 6 cm2 was 100% sensitive (range 8.1 to 35.7 cm2) in the detection of severe mitral regurgitation. For aortic regurgitation, the criterion of height of regurgitant jet to height of left ventricular outflow tract greater than 65% in the parasternal long axis view was 100% sensitive (range 71 to 100%), whereas the ratio of area of regurgitant jet to area of left ventricular outflow tract greater than 60% in the short axis view was only 36% sensitive (range 8 to 74%) in the detection of severe aortic regurgitation requiring surgery. It is concluded that the most sensitive colour flow imaging criteria for severe mitral regurgitation is an absolute mitral jet area greater than 8 cm2; and for severe aortic regurgitation, ratio of height of regurgitant jet to height of left ventricular outflow tract greater than 65%.

Doppler color-flow imaging assessment of shunt size in atrial septal defect

Two-dimensional echocardiography and pulsed-Doppler studies have not proved to be reliable methods of assessing left-to-right shunt size in atrial septal defect. Doppler color-flow imaging displays the transatrial jet, providing a new dimension with the potential capability of quantifying left-to-right shunt size. Twenty-three patients with atrial septal defect were studied by color-flow imaging and cardiac catheterization. The defect size measured by two-dimensional echocardiography, the maximal color-flow jet width in the atrial septum, and the maximal color-flow jet area in the right atrium were correlated with cardiac catheterization-derived left-to-right shunt size. Correlation coefficients were 0.57 (p less than 0.01), 0.67 (p less than 0.001), and 0.65 (p less than 0.01), respectively. Atrial septal color-flow jet width distinguished patients with less than a 2:1 left-to-right shunt size ratio (eight patients, jet width less than 15 mm in in all) from patients with greater than a 2:1 left-to-right shunt size ratio (15 patients, jet width greater than 15 mm in all). These results indicate that Doppler color-flow imaging can distinguish left-to-right shunt size in atrial septal defect accurately enough to influence decisions with regard to subsequent patient management.

Left ventricular wall motion abnormalities in subarachnoid hemorrhage: an echocardiographic study

Although electrocardiographic (ECG) abnormalities and autopsy evidence of myocardial necrosis are associated with subarachnoid hemorrhage, their relation to in vivo measures of left ventricular function in this condition has not been established. Thirteen patients with subarachnoid hemorrhage and no prior history of heart disease were studied by two-dimensional echocardiography, performed initially 10 to 48 h (mean 18) after admission and serially for less than or equal to 14 days. Serum creatine kinase (total and myocardial isoenzyme) was determined 5 times over the first 48 h; ECGs were performed daily. Neurologic state was assessed with the use of a standard grading system. Four patients (Group I) exhibited left ventricular wall motion abnormalities in one to eight segments. In two of these patients there was also left ventricular apical mural thrombus that embolized in one patient, leading to further neurologic deterioration. The initial creatine kinase myocardial isoenzyme was higher in Group I than in Group II (patients without wall motion abnormalities) (10.3 versus 2.1 U/liter, p less than 0.001), initial heart rate was higher (91 versus 61 beats/min, p less than 0.01), neurologic grade was higher (2.5 to 4.5 versus 1 to 2, p less than 0.001) and inverted T waves were more common (4 of 4 versus 1 of 9). Three of the four patients in Group I died; two of the three underwent autopsy and were found to have no significant coronary artery disease. No other patients died.(ABSTRACT TRUNCATED AT 250 WORDS)

Unlocking the mystery of systolic anterior motion: the key is timing

Though a generation has elapsed since the recognition of hypertrophic cardiomyopathy, controversy continues to rage regarding its pathophysiology. Central to the controversy is the mechanism and significance of the pressure gradient. Systolic anterior motion (SAM) of the mitral valve, as demonstrated by angiography and echocardiography, is accepted as the cause of the pressure gradient by some groups but not others. The latter authors suggest that: SAM is an incidental effect of vigorous contraction which is itself the cause of the pressure gradient and that the pressure gradient does not represent left ventricular outflow obstruction. These views are examined in light of recent studies that have assessed the temporal and quantitative relationship between SAM and the pressure gradient. It is concluded that SAM with early mitral septal contact is the cause of the pressure gradient, and represents true left ventricular outflow obstruction.

Muscular subaortic stenosis: the quantitative relationship between systolic anterior motion and the pressure gradient

We performed simultaneous echocardiographic and hemodynamic studies in 11 patients with muscular subaortic stenosis to determine whether systolic anterior motion (SAM) of the anterior mitral leaflet and the pressure gradient are related quantitatively. SAM without septal contact was associated with either no gradient or a small impulse gradient of less than 10 mm Hg. SAM with septal contact was always associated with a pressure gradient of more than 10 mm Hg. The size of the pressure gradient correlated inversely with the time periods: (1) onset of SAM-septal contact (r = .79, p less than .001) and (2) onset of aortic ejection to onset of SAM-septal contact (r = -.89, p less than .001). Size also correlated directly with the time period: (3) duration of SAM-septal contact (r = .80, p less than .001). Thus when the time from the onset of SAM to the onset of SAM-septal contact was long, SAM-septal contact developed late in systole, the duration of SAM-septal contact was brief and the pressure gradient was low. When SAM-septal contact developed in early systole, the duration of SAM-septal contact was long and the pressure gradient was high. With the index of time period (3) divided by time period (1), a regression equation was devised to predict the size of the pressure gradient (pressure gradient [mm Hg] = 25 [ratio] + 25; r = .90, p less than .001; SE +/- 15 mm Hg). The echocardiographic time period index was validated prospectively in nine other patients and the significant correlation with the hemodynamically determined gradient persisted (r = .89, p less than .01). We conclude that SAM and the pressure gradient are related quantitatively in muscular subaortic stenosis. These observations have implications regarding the mechanism and significance of the pressure gradient in muscular subaortic stenosis.

Variability of digitized echocardiography: size, source, and means of reduction

Digitization of M-mode echocardiograms provides useful information on left ventricular function, but its variability has been assessed rarely. Inter- and intraobserver (technical) variability of readers digitizing the same cardiac cycles, and variability between beats, days, and subjects (biologic) was determined. Technical variability was small for both standard dimensions (correlation coefficient r values 0.82 to 1.00) and rates of change (r values 0.70 to 0.98). Biologic variability was large with expected normal differences between 2 measurements (95% confidence limits) of 11 to 55% and 37 to 106% for standard dimensions and rates of change, respectively. By averaging measurements of 5 beats from each of 2 days, the expected normal differences are reduced to 6 to 32% and 23 to 63% for standard dimensions and rates of change. This study emphasizes the large biologic variability in rates of change of digitized left ventricular measurements. Normal variation between studies can be reduced and real physiologic or pathologic changes perceived best if many beats from more than 1 day are measured.