We Take Your Health to Heart

Our Heart Rhythm Center Doctors 

A team of electrophysiologists, nurses, technologists, research staff, cardiac resynchronization therapy specialists and Holter monitor specialists make up the Cardiac Arrhythmia Service and Electrophysiology Lab at our medical centers. 

Our specialists treat a variety of patients, including younger and older patients, pregnant women with arrhythmias, patients with atypical symptoms or unique conditions, patients with familial conditions, and patients that require pacemakers, implantable cardioverter defibrillators or biventricular devices. 


Thomas A. Mattioni, M.D.

Medical Director of Electrophysiology

Dr. Mattioni is managing partner of Arizona Arrhythmia Consultants in Scottsdale. Previously he was director of electrophysiology at the Arizona Heart Institute in Phoenix from 1991 to 2003. 

He received his medical degree in 1981 from Northwestern University Medical School in Chicago, followed by his internship and residency in internal medicine at Northwestern Memorial Hospital from 1981 to 1984. He completed two fellowships, one in cardiology and another in clinical cardiac electrophysiology at Northwestern’s medical school between 1984 and 1987. 

Dr. Mattioni’s academic teaching experience includes a current position as adjunct assistant professor of medicine at the Arizona College of Osteopathic Medicine. Previously, he was assistant professor of medicine at the University of Maryland School of Medicine in Baltimore, where he also was director of clinical cardiac electrophysiology for the laboratory and arrhythmia service and director of the ECG Center. 

Earlier in Chicago, Dr. Mattioni was an instructor of medicine at Northwestern University Medical Center.


Renzo Cataldo, M.D.

Focusing on clinical cardiac electrophysiology since 2001 in Arizona, Dr. Cataldo practiced in Albuquerque previously and was a clinical assistant professor of medicine at the University of New Mexico School of Medicine. 

Originally from Brooklyn, he earned his medical degree at the Universita’ degli Studi di Trieste in Trieste, Italy. He completed his internal medicine internship at St. Vincent’s Medical Center of Richmond in Staten Island, N.Y. and an internal medicine residency at the Long Island Jewish Medical Center in New Hyde Park, N.Y. Moving to Salt Lake City, he completed cardiology and electrophysiology fellowships at the University of Utah. 

Dr. Cataldo began his career in academia and later went into private practice. He was an assistant professor of medicine at Loyola University Stritch School of Medicine in Chicago and served as director of electrophysiology at the University of New Mexico Health Sciences Center in Albuquerque. 

He is board certified in internal medicine, cardiology and electrophysiology. He assists physicians in the diagnosis and management of complicated rhythm problems that do not respond to conventional treatment.  


David Riggio, M.D.

Assistant Director of Electrophysiology for the Clinical Research Department of Arizona Arrhythmia Consultants in Scottsdale since 2003, Dr. Riggio held the same position for 10 years with Arizona Heart Institute in Phoenix. He has been affiliated with Scottsdale Healthcare since 1994. 

He is a graduate of the Keck School of Medicine of the University of Southern California. He completed two internal medicine residencies and one cardiology fellowship at the Los Angeles County/University of Southern California Medical Center, and another fellowship at the University of Maryland Hospital in Baltimore. 

In addition, he was Chief Administrative Fellow for the Department of Cardiology for Los Angeles County and the University of Southern California Medical Center in 1992-93. 

Dr. Riggio is board certified in both internal medicine and cardiac electrophysiology.

Michael Zawaneh, M.D.

A native Floridian, Dr. Zawaneh is attracted to the challenges and intricacies of electrophysiology, "Electrophysiology is a constantly evolving and challenging field. It allows me not only to personally care for my patients, but also aspire to make a positive difference in the quality of their lives." After attending University of Florida Medical School, Dr. Zawaneh's path led him first to Cleveland's Case Western University Hospital and then The Cleveland Clinic where he was a resident and fellow. It was in Cleveland that Dr. Zawaneh's abilities and demeanor with patients came to the attention of AAC, where in the summer of 2010, he joined the AAC team. Dr. Zawaneh is certified by the Cardiovascular American Board of Internal Medicine and the American Board of Internal Medicine.



Andy H. T. Tran, M.D.

A practicing cardiologist at Cardiovascular Consultants Ltd. Since 2006, Dr. Tran is a graduate of St. George’s University School of Medicine in Grenada, West Indies. 

He completed his internship and residency in internal medicine at MCP Hahnemann University in Philadelphia and his fellowship in cardiovascular disease at Wayne State University in Detroit. His fellowship at Henry Ford Hospital in Detroit was in electrophysiology. 

Dr. Tran has his board certifications in internal medicine with subspecialties in cardiovascular disease and electrophysiology.