Final answer:
Autonomic tone is critical in cardiovascular disease because it regulates blood pressure and heart rhythm, with an imbalance contributing to hypertension and arrhythmias, common risk factors for heart disease.
Step-by-step explanation:
The importance of autonomic tone in the context of cardiovascular disease lies in how the balance between the sympathetic and parasympathetic nervous systems affects heart function. Autonomic tone indicates the level of influence the nervous system has on an organ in its resting state. With respect to the cardiovascular system, specifically, an imbalance can affect blood pressure regulation and heart rhythm.
Increased sympathetic tone in the blood vessels, often with limited parasympathetic influence, will cause vasoconstriction and an increase in blood pressure. Moreover, since the heart is intrinsically active, the autonomic nervous system modulates its activity; the sympathetic nervous system increases the heart rate, while the parasympathetic nervous system decreases it. These systems do not merely cancel each other out; rather, they may present conflicting signals that result in arrhythmias--a risk factor for cardiovascular disease.