Mark E. Leithe M.D.

IntroductionDoctors who specialize in the diagnosis and treatment of conditions or diseases of the cardiovascular system (the heart and blood vessels) are called heart doctors or cardiologists. These specialists are trained to identify, treat, and help prevent heart issues. There are also different...

SymptomsThe affected person may exhibit one or more of the following symptoms. Symptoms are not always consistent, as they may flare up or disappear at any time. ...

Our heart rate is automatically controlled by the autonomic nervous system (ANS) that has two divisions: sympathetic and parasympathetic. The part of the ANS that is responsible for raising a person’s heart rate through the sympathetic plexus is the sympathetic division. The parasympathetic...

Heart palpitations, although it feels like a scary experience, are not always a sign of something serious. These palpitations are harmless but there are some instances when it could be a signal to a serious heart disease, especially if it is associated with other symptoms. This article explains...

High blood pressure or hypertension is a chronic condition that may lead to other complications, including organ damage, gradually over a period of time. The blood pressure may become very high and severe all of a sudden resulting in a condition referred to as hypertensive crisis. Hypertensive...

IntroductionNicotine is an alkaloid stimulant that comes from the nightshade family of plants, particularly from the leaves of tobacco. The type of nicotine found in tobacco plants is called Nicotiana tabacum. Nicotine can also be synthetically produced. Thousands of chemicals are contained in...