The clinical manifestations of cardiac diseases are complex and varied, often combined with a variety of co-morbidities, which significantly increases the difficulty of diagnosis and treatment of the disease and clinical risk. The “syndrome-based approach” is to take the syndromes as the core and integrate different diseases into a unified framework to grasp the whole. This model emphasizes the simplification of complex clinical problems by comprehensively analyzing the underlying syndromes, grasping the core disease mechanism, and combining it with the dynamic evolution of the disease. Although the evolution of the disease follows a certain pattern, it is by no means a mechanical application, but needs to be organically integrated with the “evidence” and flexibly utilized. Cardiac qi deficiency is a common pathogenetic mechanism throughout the development of cardiac diseases. Based on the evidence of heart qi deficiency, this paper systematically proposes three major laws for the evolution of cardiac diseases: the theory of four levels of heart qi deficiency (to quantify the severity of symptoms), the theory of three levels of accumulation of internal organs (to explain the pathway of disease transmission), and the pathological transformation of “water-dampness-phlegm-blood stasis” (to reveal the evolution of pathological products). The management model of cardiac diseases was constructed with this framework, and the heterogeneous characteristics of the five aspects of disease location, disease condition, degree, concurrent symptoms and concurrent diseases were summarized while taking into account the commonality of the same evidence. The aim of this paper is to provide diagnostic and therapeutic ideas with Chinese medicine characteristics for the clinical management of cardiac diseases, and to improve clinical efficacy by optimizing evidence-based thinking.