Mechanical Function of the Atrial Diastole: A New Discovery

This eminently readable book by Dr. Dinker B. Rai, the long-time Chief of Vascular Surgery and Chairman of the Department of Surgery at Interfaith Medical Center, an iconic institution formerly known as the Jewish Hospital and Medical Center in Brooklyn, NY, is not the traditional scientific monograph that the title would suggest. It is partly memoir, partly a medical history of circulation, and partly scientific hypothesis based on a briefly summarized set of animal experiments. The style is definitely not that of a typical medical manuscript. With a touch of Hemingway, the author weaves the disparate sections into a memorable whole of his personal journey through tradition, enquiry, anguish, and the sudden dawning of an epiphany, a culmination of the subconscious immersed on the riddle all the time, awake and asleep. The suction force of the atrial diastole is clearly the missing piece of the puzzle for the author. The years of mind-wandering in the wilderness would now mercifully cease. The “Mechanical Function of the Atrial Diastole: A New Discovery” is the final effervescence of that magnificent obsession. This is not to say that the book is without scientific value. Quite the contrary, initial chapters are based on deep research of history from the time of Aristotle to present, and the rest of the chapters are the outcome of tedious scientific research based on animal experiments. It is certain to become reference sources.

The sections of the book dealing with the History of the Circulation ranging from antiquity to the present is an example. The author learned Sanskrit himself to scour ancient texts on the topic. Dr. Rai illustrates historical concepts of circulation from the pre-Galenic era to present with charming colored hand drawings in his own unique style which are definitely decorative to the book and easily illustrative to the reader. The middle ages are covered in great detail with interesting tidbits about William Harvey and his intellectual forebearers.

If there is a gap in the historical narration, it is the last quarter of the last century. Vis e Fronte and Vis e Tergo are scarcely mentioned. Guyton, whose equations of circulation hold dominant sway over current concepts of circulatory control, gets the silent rejection without verbal combat. But the last few chapters, which describe the author's seminal experiments, demonstrate that the suction action of the right atrium is a powerful riposte to Guyton's theories. However, Guyton did not ever explicitly deny a role for the atria. His experiments demonstrating peripheral control (venous return) of cardiac output incorporated right atrial bypass as part of the experimental design. The role of the right atrium was thus camouflaged in his experiments. This along with other observations conflicting with Guyton's theories has drawn valid criticism. An evolving reappraisal would regard venous compliance and cardiac action as interdependent variables.

Dr. Rai for his part does not claim exclusivity for his atrial suction concept. He acknowledges that the muscle content of veins and the peripheral heart in the lower limb plays a role in homeostasis.

This fascinating book should prompt experiments to synthesize two circulatory control concepts that are not mutually exclusive.

Publication History

Article published online:
12 September 2022