Assessment of regional left ventricular filling dynamics using color kinesis in patients with hypertrophic cardiomyopathy

Echocardiographic tissue imaging evaluation of myocardial characteristics and function in cardiomyopathies

Current echocardiography techniques have allowed more precise assessment of cardiac structure and function of the several types of cardiomyopathies. Parameters derived from echocardiographic tissue imaging (ETI)-tissue Doppler, strain, strain rate, and others-are extensively used to provide a framework in the evaluation and management of cardiomyopathies. Generally, myocardial function assessed by ETI is depressed in all types of cardiomyopathies, non-ischemic dilated cardiomyopathy (DCM) in particular. In hypertrophic cardiomyopathy (HCM), ETI is useful to identify subclinical disease in family members of HCM, to differentiate HCM from other conditions causing cardiac hypertrophy and to predict cardiac events. ETI also for HCM allows addressing the mechanism behind left ventricular outflow tract obstruction and its improvement after therapeutic options. ETI provides cardiac amyloidosis with unique and specific findings such as "apical sparing." Nevertheless, ETI does not seem to provide as much information amenable to histological findings as recently emerging techniques of cardiac magnetic resonance imaging. This review introduces usefulness of ETI and some other ultrasound techniques for detecting clinical and subclinical characteristics of cardiomyopathies, focusing on DCM, HCM, and cardiac amyloidosis.

Intraoperative coronary artery pulse Doppler patterns in patients with complete transposition of the great arteries undergoing the arterial switch operation

BACKGROUND

Arterial switch operation is standard repair for complete transposition of the great arteries (TGA). Coronary artery abnormalities are the most common cause of morbidity and mortality in the acute postoperative phase. This study was designed to determine whether coronary artery pulse Doppler flow patterns obtained by transesophageal echocardiography during the arterial switch operation are correlated with acute postoperative outcomes.

METHODS

A retrospective review of all patients with TGA undergoing the arterial switch operation between 2004 and 2006 was performed. Intraoperative coronary artery pulse Doppler flow patterns were analyzed by 2 blinded investigators. Associations of coronary artery pulse Doppler flow patterns with clinical outcomes were sought using multivariable linear and logistic regression analysis.

RESULTS

Sixty-three patients (48 male, gestational age 38 +/- 2 weeks, birth weight 3,514 +/- 613 g) were analyzed. Three patients needed mechanical support (2 died), 19 had delayed sternal closure, 17 had arrhythmias, and 9 had ST changes. The most common coronary artery pulse Doppler flow pattern consisted of a late systolic peak followed by low-velocity flow throughout diastole. A left main coronary artery (LMCA) velocity time integral >0.14 (P = .01) and an LMCA peak systolic velocity >0.6 cm/s (P = .05) were associated with need for surgical revision.

CONCLUSION

Abnormalities in LMCA flow were associated with the need for surgical revision in patients with TGA undergoing the arterial switch operation. Normal coronary artery pulse Doppler flow patterns after the arterial switch operation consisted of a late systolic peak followed by low-velocity flow throughout diastole.

The usefulness of Doppler myocardial imaging in the study of the athlete's heart and in the differential diagnosis between physiological and pathological ventricular hypertrophy

Athlete's heart is a cardiac adaptation to long-term, intensive training, which includes changes as increased ventricular cavity diameters, wall thickness and mass, produced with a degree consistent with sports activities and exercise programs. The Doppler myocardial imaging (DMI) permits characterization of the velocities of each ventricular myocardial segment by placing the sample volume at the center of the cardiac muscle. Even if the standard two-dimensional (2D) echocardiography represents an irreplaceable method in the evaluation of cardiac adaptations to physical exercise, the data currently available suggests the usefulness of DMI in the assessment of the myocardial systolic and diastolic functions of the athlete's heart. In particular, an athlete's left ventricular hypertrophy is characterized by a "supernormal" DMI pattern, with increased myocardial early-diastolic velocity. Therefore, DMI analysis in the trained subject has demonstrated interesting prospective for: (1) the differential diagnosis from pathological, both, left and right ventricular hypertrophy; (2) the prediction of cardiac performance during physical effort; (3) the evaluation of the biventricular interaction; (4) the analysis of the myocardial adaptations to various training protocols; and (5) the early identification of specific genotypes associated with cardiomyopathies. On this ground, a combined use of standard 2D echo and DMI may be taken into account for a valid noninvasive and easy-repeatable evaluation of both physiological and pathological ventricular hypertrophies.

Tissue Doppler imaging for the evaluation of patients with hypertrophic cardiomyopathy

PURPOSE OF REVIEW

To discuss the role of tissue Doppler imaging for assessing regional myocardial function in patients with proven or suspected hypertrophic cardiomyopathy and review its application in clinical practice for diagnosis, estimation of filling pressures, and monitoring of treatment.

RECENT FINDINGS

Patients with hypertrophic cardiomyopathy have very abnormal systolic and diastolic myocardial function, even if global systolic function of the left ventricle appears normal. Regional function is most abnormal in walls that are markedly hypertrophied, but it is also abnormal in segments that are not affected by hypertrophy, and it is depressed in patients who have a mutation for hypertrophic cardiomyopathy but have not yet developed clear phenotypic changes. Genetic diagnosis remains difficult especially in sporadic cases, due to the very large number of mutations that have been identified; the hypertrophy may represent a nonspecific compensatory response to any mutation that impairs myofibrillar function. Subclinical changes especially affect long-axis ventricular function, and tissue Doppler imaging is the most sensitive test to identify reduced velocities of long-axis shortening and early diastolic lengthening of the left ventricle, prolonged contraction and relaxation times, and reduced strain in affected segments, both in patients with hypertrophy and in asymptomatic subjects with mutations. It can also discriminate well between hypertrophic cardiomyopathy and athlete's heart, and can be used with standard echocardiographic measurements to estimate left ventricular filling pressure or to monitor treatment.

SUMMARY

Tissue Doppler imaging can now be usefully incorporated into the routine echocardiographic study of patients with proven or suspected hypertrophic cardiomyopathy.