Walking with Gianluca Di Bella during the development of clinical cardiac imaging

Abstract

Cardiac magnetic resonance imaging (MRI) for the diagnosis and management of many cardiac diseases has been established in clinical practice. It provides anatomic and functional information and is the most precise technique for quantification of ventricular volume, function and mass. Among cardiac MRI sequences used in clinical practice, delayed contrast enhancement is an accurate and reliable method used in the diagnosis of ischemic and nonischemic cardiomyopathies. In addition, new technology applied in echocardiographic imaging has permitted quantification of myocardial deformations with 2-dimensional strain imaging (longitudinal, circumferential and radial strain). Cardiac MRI and echocardiography therefore both play a crucial role in the diagnosis and management of cardiovascular disease. Dr. Di Bella and colleagues have defined the roles of cardiac MRI and echocardiography in many clinical and experimental settings.

Key Words: Cardiac magnetic resonance imaging; Strain echocardiography; Myocarditis; Myocardial infarction; Cardiomyopathy; Heart failure

INTRODUCTION AND EDUCATIONAL EXPERIENCE

Dr. Gianluca Di Bella (Figure 1) is a Professor of Cardiology and researcher in the Faculty of Medicine and Surgery at the University of Messina, Italy. He received his first class degree in the Faculty of Medicine and Surgery at the University of Messina in 2001. He was certified as a specialist in cardiovascular disease at the University of Messina in 2005. He pursued graduate work on the application of cardiac magnetic resonance in the magnetic resonance imaging (MRI) laboratory at the Clinical Physiology Institute (CNR), Pisa, Italy under Dr. Lombardi M in 2004-2005. He received training in the application of cardiac magnetic resonance and computed tomography in the Radiological Department of the University Hospital of Leuven (Belgium) under Prof. Dr. Bogaert J in 2007. He received PhD qualification in “methodologies and techniques of cardiovascular imaging” at the University of Messina, Italy in 2009. His research has been supported by research grant and fellowship awards from the Italian Society of Cardiology since 2004. As an independent investigator, he received the young researcher award from the Italian Society of Cardiology in 2006 and 2008. He is a reviewer for international journals and plays a key role in the Italian Society of Cardiology (e.g. vice-chairman of the cardiac MRI working group) and Italian Society of Echocardiography (e.g. member of the task force on integrated cardiac imaging).

Figure 1 Gianluca Di Bella, MD, PhD, Clinical and Experimental Department of Medicine and Pharmacology, Faculty of Medicine, University of Messina, via Consolare Valeria N 1, CAP 98100, Messina, Italy.

RESEARCH FOCUS AND STRATEGIES

Over recent years, Dr. Di Bella’s research group has investigated cardiovascular diseases using cardiac MRI and strain echocardiography. An integrated approach with MRI and echocardiography provides an excellent and useful tool that permits identification of the pathophysiology of cardiovascular diseases. Dr. Di Bella’s research has permitted identification of the relationship between myocardial damage and deformation in acute myocarditis[1-6]. Furthermore, Dr. Di Bella’s research has included the study of clinical signs of heart failure, systolic function and cardiomyopathies[7-17].

Another focus of Dr. Di Bella’s research has been on cardiac imaging in patients with myocardial infarction[18-32], heart valve disease[33,34], atrial septal defect[35] and congenital anomalies[36-38]. He has authored papers on the correlation between percutaneous transluminal coronary angioplasty (PTCA) time and acute myocardial damage during ST elevation myocardial infarction[18], the relation between Q waves and scar tissue[20], the evidence that obese patients have less scar tissue than patients without obesity (obesity paradox)[22] and the correlation between scar tissue and non-sustained ventricular tachycardia[23]. Recently, he identified early MRI signs in patients with cardiac amyloidosis[39].

RESEARCH ACHIEVEMENTS

The following highlight Dr. Di Bella’s contributions in the field of cardiac imaging, diagnosis and pathophysiology of cardiac diseases.

Role of cardiac MRI and echocardiography in the diagnosis and pathophysiology of acute myocarditis

Di Bella et al[1] demonstrated the role of cardiac MRI in the diagnosis of focal myocarditis, even with the lack of wall motion abnormalities. Furthermore, Di Bella et al[2,3,6] identified the role of endocardium and epicardium in left ventricular deformation. They showed that both longitudinal and circumferential myocardial deformations were impaired in patients with acute myocarditis with preserved wall motion and evidence of subepicardial damage[3]. Particularly, longitudinal strain was reduced in all myocardial walls independently from the presence or absence of subepicardial damage, although segments with subepicardial damage had greater impairment of longitudinal strain than those without damage. This suggests that subepicardium contributes together with subendocardium to longitudinal strain.

New advances of echocardiography and cardiac MRI in cardiac function

Cardiac function and its pathophysiology were studied by Dr. Di Bella and colleagues in different clinical and experimental settings. Di Bella et al[7] studied cardiac function during hypoxemia induced by prolonged breath holding (in air) in healthy diving athletes. Results showed that, during breath holding, the stroke volume and cardiac output increased due to recruitment of left ventricle preload reserve, which counterbalanced the reduction in systolic function.

Others studies investigated the role of symptoms and signs in identifying left ventricular dilatation and/or systolic dysfunction[7,8]. Recently, Di Bella et al[10] showed that strain echocardiography allows an accurate, rapid, easy and reliable semiautomatic quantification of the left ventricular ejection fraction.

Scar tissue and myocardial infarction: new observations using cardiac MRI

Dr. Di Bella and colleagues published studies on the role of scar tissue in patients with acute and chronic myocardial infarction. The most interesting results have demonstrated the following: (1) the impact of no reflow and scar tissue in patients with ST elevation myocardial infarction and the relation with PTCA time[18]; (2) the capability of cardiac MRI in simultaneous visualization of myocardial scar, no-reflow phenomenon and ventricular and atrial thrombi[19]; (3) the relationship between regional function and scar tissue[20]; (4) the predictive role of Q waves to identify localization and extension of scar tissue[21]; (5) the relationship between body mass index and scar tissue[22]; and finally; and (6) the combined role of regional function and scar tissue in the genesis of non-sustained ventricular tachycardia[23]. In this latter study, entitled “Different substrates of non-sustained ventricular tachycardia in post-infarction patients with and without left ventricular dilatation,” Dr Di Bella showed that necrotic and viable myocardium coexistence within the same wall segments predicts occurrence of non-sustained ventricular tachycardia in patients without left ventricular dilatation, whereas left ventricular mass and end-systolic volume are predictors of non-sustained ventricular tachycardia in those with left ventricular dilatation.

Early identification of cardiac amyloidosis by cardiac MRI

The diagnosis of early stage cardiac amyloidosis is very difficult, however, studies have shown that cardiac MRI is a helpful tool for identification of amyloidotic deposition in patients with heart failure due to amyloidosis. Di Bella et al[39] showed that cardiac MRI is a suitable technique to identify cardiac amyloidosis in asymptomatic patients. In this paper, Di Bella and colleagues showed an unusual localization of myocardial damage (hyperenhancement) in mid-basal segments of inferior and inferolateral walls. Furthermore, they observed an enhancement of the atria and/or tricuspid valve and/or right ventricle in all patients affected by cardiac deposition of amyloidosis.

Outcome in patients with suspected arrhythmogenic right ventricular dysplasia

Aquaro et al[40] studied the role of right ventricular (RV) abnormalities detected by cardiac MRI to predict adverse outcome in patients with suspected arrhythmogenic right ventricular dysplasia (ARVD). They showed that RV abnormalities are also associated with worse outcomes in patients without a definite diagnosis of ARVD.

CONCLUSION

Cardiac imaging has greatly modified the diagnostic process with noninvasive, rapid and accurate diagnosis of cardiac diseases. Echocardiography is the first step of cardiac imaging while an appropriate use of cardiac MRI is mandatory for identification of the substrate of many diseases. Overall, Dr. Di Bella’s research has contributed to a better understanding of the role of strain echocardiography and cardiac MRI in clinical practice.