Evaluating left atrial strain and left ventricular diastolic strain rate as markers for diastolic dysfunction in patients with mitral annular calcification

BACKGROUND

Mitral annular calcification (MAC) poses many challenges to the evaluation of diastolic function using standard echocardiography. Left atrial (LA) strain and left ventricular early diastolic strain rate (DSr) measured by speckle-tracking echocardiography (STE) are emerging techniques in the noninvasive evaluation of diastolic function. We aim to evaluate the utility of LA strain and early DSr in predicting elevated left ventricular filling pressures (LVFP) in patients with MAC and compare their effectiveness to ratio of mitral inflow velocity in early and late diastole (E/A).

METHODS

We included adult patients with MAC who presented between January 1 and December 31, 2014 and received a transthoracic echocardiogram (TTE) and cardiac catheterization with measurement of LVFP within a 24-h period. We used Spearman's rank correlation coefficient to assess associations of LA reservoir strain and average early DSr with LVFP. Receiver operating characteristic (ROC) curves were computed to assess the effectiveness of LA strain and DSr in discriminating elevated LVFP as a dichotomized variable and to compare their effectiveness with E/A ratio categorized according to grade of diastolic dysfunction.

RESULTS

Fifty-five patients were included. LA reservoir strain demonstrated poor correlation with LVFP (Spearman's rho = 0.03, p = 0.81) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.54, 95% CI 0.38-0.69). Categorical E/A ratio alone also demonstrated poor discriminatory ability (AUC = 0.53, 95% CI 0.39-0.67), and addition of LA reservoir strain did not significantly improve effectiveness (AUC = 0.58, 95% CI 0.42-0.74, p = 0.56). Average early DSr also demonstrated poor correlation with LVFP (Spearman's rho = -0.19, p = 0.16) and poor discriminatory ability for detecting elevated LVFP (AUC = 0.59, 95% CI 0.44-0.75). Addition of average early DSr to categorical E/A ratio failed to improve effectiveness (AUC = 0.62, 95% CI 0.46-0.77 vs. AUC = 0.54, 95% CI 0.39-0.69, p = 0.38).

CONCLUSIONS

In our sample, LA reservoir strain and DSr do not accurately predict diastolic filling pressure. Further research is required before LA strain and early DSr can be routinely used in clinical practice to assess filling pressure in patients with MAC.

Left atrial strain, embolic stroke of undetermined source, and atrial fibrillation detection

BACKGROUND

Atrial cardiopathy is a proposed mechanism of embolic stroke of undetermined source (ESUS). Left atrial (LA) strain may identify early atrial cardiopathy prior to structural changes. We aim to study the associations between LA strain, ESUS, and atrial fibrillation (AF) detection in ESUS.

METHODS

The study population included patients with ESUS and noncardioembolic (NCE) stroke presenting to the Rhode Island Hospital Stroke Center between January 2016 and June 2017 who underwent transthoracic echocardiography. Speckle tracking echocardiography (STE) was used to measure the three phases of LA strain (reservoir, conduit, and contractile). Binary logistic regression analysis was performed to determine the associations between LA strain and stroke subtype (ESUS vs. NCE) as well as follow-up detection of AF in ESUS patients.

RESULTS

We identified 656 patients, 307 with ESUS and 349 with NCE. In binary logistic regression, the lowest tertiles of LA reservoir (adjusted OR 1.944, 95% CI 1.266-2.986, p = .002), contractile (aOR 1.568, 95% CI 1.035-2.374, p = .034), and conduit strain (aOR 2.288, 95% CI 1.448-3.613, p = .001) were more likely to be significantly associated with ESUS compared to NCE stroke. Among all ESUS patients, the lowest tertiles of LA reservoir strain (OR 2.534, 95% CI 1.029-6.236, p = .043), contractile strain (OR 2.828, 95% CI 1.158-6.903, p = .022), and conduit strain (OR 2.614, 95% CI 1.003-6.815, p = .049) were significantly associated with subsequent detection of AF.

CONCLUSION

Reduced LA strain is associated with ESUS occurrence and AF detection in ESUS patients. Therefore, quantification of LA strain in ESUS patients may improve risk stratification and guide secondary prevention strategies.

Insights Into the Standard Echocardiographic Views From Multimodality Imaging: Ventricles, Pericardium, Valves, and Atria

The widespread use of cardiac computed tomography and cardiac magnetic resonance imaging in patients undergoing echocardiography presents an opportunity to correlate the images side by side. Accordingly, the aim of this report is to review aspects of the standard echocardiographic examination alongside similarly oriented images from the two tomographic imaging modalities. It is hoped that this exercise will enhance understanding of the structures depicted by echocardiography as they relate to other structures in the thorax. In addition to reviewing basic cardiac anatomy, the authors take advantage of these correlations with computed tomography and cardiac magnetic resonance imaging to better understand the issue of foreshortening, a common pitfall in transthoracic echocardiography. The authors also highlight an important role that three-dimensional echocardiography can potentially play in the future, especially as advances in image processing permit higher fidelity multiplanar reconstruction images.

Insight into different phenotypic presentations of heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for half of all HF diagnoses, and its prevalence is increasing at an alarming rate. Lately, it has been recognized as a clinical syndrome due to diverse underlying etiology and pathophysiological mechanisms. The classic echocardiographic features of HFpEF have been well described as preserved ejection fraction (≥50%), left ventricular hypertrophy, and left atrial enlargement. However, echocardiography can play a key role in identifying the principal underlying mechanism responsible for HFpEF in the individual patient. The recognition of different phenotypic presentations of HFpEF (infiltrative, metabolic, genetic, and inflammatory) can assist the clinician in tailoring the appropriate management, and offer prognostic information. The goal of this review is to highlight several key phenotypes of HFpEF and illustrate the classic clinical scenario and echocardiographic features of each phenotype with real patient cases.

Serial echocardiography for valve dysfunction and aortic dilation in bicuspid aortic valves

BACKGROUND AND AIMS

Complications of bicuspid aortic valve commonly include aortic stenosis, aortic regurgitation, and ascending aortic dilation. The progression of these lesions is not well described.

MATERIALS AND METHODS

We reviewed 249 bicuspid aortic valve patients with at least two echocardiograms from 2006 to 2016. Valve morphology (right-left or right-noncoronary cusp fusion) was confirmed by visual inspection, and aortic stenosis and regurgitation were quantified according to current guidelines; the ascending aorta was measured at end-systole 2-3 cm above the sinotubular junction. Annualized progression of stenosis, regurgitation, and aortic dilation from first to most recent echocardiogram were compared between right-left and right-nonfused valves using multivariable logistic regression to adjust for baseline differences in groups.

RESULTS

Among 249 bicuspid aortic valve patients (mean age 47.6 ± 13.5 years, 66.3% male), 75.9% had right-left cusp fusion. At baseline, aortic stenosis was absent or mild in 80.3%; aortic regurgitation was absent or mild in 80.7%; and aortic diameters were 35.0 ± 5.7 mm (sinuses of Valsalva) and 37.4 ± 6.2 mm (ascending). Mean annualized decrease in aortic valve area was 0.07 cm² /year, with 30% of bicuspid aortic valve patients progressing ≥0.1 cm² /year. Aortic regurgitation progressed ≥1 grade in 37 patients. Mean annualized increase in ascending aorta diameter was 0.36 mm/year in right-left and 0.65 mm/year in right-nonbicuspid valves.

CONCLUSIONS

In this serial echocardiographic study of bicuspid aortic valve patients, cusp orientation was not associated with progression of valve dysfunction. Right-noncoronary cusp fusion was associated with ascending aortic diameter progression.

Intraocular gentamicin sulfate and postcataract anterior chamber aspirate cultures

We cultured anterior chamber aspirates of 28 patients who had uncomplicated cataract surgery. Fourteen patients had received 80 micrograms/ml of gentamicin in balanced salt solution through irrigation of the anterior chamber throughout cataract extraction, and 14 patients had received 8 micrograms/ml of gentamicin. Cultures of anterior chamber fluid obtained at the end of surgery from all 28 patients had no growth on two nonselective media. There was no clinical evidence of ocular toxicity. This study demonstrates that antibiotic in the intraocular irrigation fluid can reduce or eliminate the expected intraocular bacterial load after cataract surgery.

Periocular FK-506 delays allograft rejection in rat penetrating keratoplasty

FK-506 is a new immunosuppressant with the ability to inhibit activation of T-lymphocytes that would be cytolytic to an allograft. We studied periocular injection of FK-506 in a rat penetrating keratoplasty model. Corneas were transplanted from Brown Norway rats into Lewis rat recipients. The transplanted rats received periocular injection of either 0.5 mg/kg FK-506 or an equivalent volume of FK-506 vehicle only. Injections were given 1 day before, at keratoplasty, and every other day after keratoplasty until allograft rejection. The group receiving FK-506 had a significant delay in allograft rejection (p < 0.05). The FK-506 group rejected 12-20 days postkeratoplasty with a mean rejection time (MRT) of 14.3 days, compared with 8-14 days (MRT 11.1 days) for the control group. We conclude that periocular administration of FK-506 is effective in prolonging allograft survival in the rat penetrating keratoplasty model.

Transient posterior subcapsular lens opacities in diabetes mellitus

In three patients with transient cataracts the lenticular opacities were feathery in nature, and posterior subcapsular in location. They appeared to emanate from a dense central posterior subcapsular plaque. These opacities were examined with the slit lamp and documented photographically. The onset of cataract was abrupt in all three patients, and resolved over a three- to 36-day period. Two patients had bilateral reversible cataracts, and in one of these patients the lenticular opacities were recurrent. Two of the patients had been taking oral corticosteroids. Temporary cataracts have been previously reported in patients with poor diabetic control. Diabetes mellitus had been diagnosed in only one of our patients. Three-hour glucose tolerance testing of the other two patients disclosed mildly increased one-hour blood glucose levels. We believe that reversible lens opacities may occur in subclinical diabetes mellitus with normal or only mildly increased blood glucose levels.

Atypical magnetic resonance findings in an orbitofrontal cholesterol granuloma

Cholesterol granuloma of the orbit is an uncommon entity, although it frequently occurs in the middle ear and petrous apex. It is isodense with brain on computed tomographic scanning and cannot always be differentiated from more serious conditions. Magnetic resonance imaging (MRI) has facilitated the preoperative diagnosis of cholesterol granuloma outside of the orbit because of high signal characteristics on T1- and T2-weighted images. These findings have been considered nearly pathognomonic, but they have previously been described in only one patient with orbitofrontal involvement. We present a case of orbitofrontal cholesterol granuloma with uncharacteristic signal intensities on magnetic resonance imaging.

Anterior chamber aspirate cultures after uncomplicated cataract surgery

We cultured anterior chamber aspirates of 30 patients who had uncomplicated extracapsular cataract extraction or phacoemulsification. The aspirate was obtained at the time of wound closure. Of 30 patients, 13 (43%) had culture-positive anterior chamber aspirates. The total number of organisms recovered was 18, with three patients having multiple organisms identified. The most commonly isolated organisms were coagulase-negative Staphylococcus sp., occurring in eight of 18 isolates (44%). No eyes in our study developed endophthalmitis, even though almost one half had viable organisms growing from the anterior chamber aspirates. Inoculum sizes were extremely small (10 to 20 colony-forming units/ml). This study suggests that in humans, the anterior chamber is capable of clearing a low inoculum of bacteria after cataract surgery without the development of endophthalmitis.

Endogenous Candida endophthalmitis after intravenous anesthesia with propofol

Propofol is an intravenous anesthetic agent that was approved by the US Food and Drug Administration in October 1989. It has gained rapid acceptance and is in widespread use. In June 1990, the Centers for Disease Control reported four clusters of postsurgical infections associated with the use of propofol. We describe one of those clusters, consisting of four cases of endogenous Candida albicans endophthalmitis. These infections occurred in nonimmunocompromised patients after they had undergone nonophthalmologic surgery in which propofol had been used as anesthesia. An investigation by the Centers for Disease Control concluded that the infections in these patients were due to extrinsic contamination of propofol during preparation for use at the hospital. Ophthalmologists should be aware of this new potential source of endogenous endophthalmitis.