The recommended limit of caffeine during pregnancy is 200 milligrams (mg) a day. So with a typical soda containing 35 to 55 mg of caffeine, it's wise to limit yourself accordingly, and take into account other sources of caffeine in your diet, such as coffee, tea, and energy drinks.
If you have a known heart problem, such as heart failure or heart disease, PVCs may be a sign that a dangerous heart rhythm could occur. So if you have a heart problem, talk to your doctor if you feel any change in your heartbeat. The cause of PVCs usually isn't known. But the chance of having PVCs can be increased by: 1  Having too much or too little of certain minerals (electrolytes) in your body. 2  Having too little oxygen in your blood, which could happen if you have COPD or pneumonia. 3  Using some medicines, such as albuterol.
Premature ventricular contractions (PVCs) are premature heartbeats originating from the ventricles of the heart. Premature ventricular contractions are premature because they occur before the regular heartbeat.Normal function of the heart. The heart has four chambers.The upper two chambers are the atria, and the lower two chambers are the ventricles.he SA node is the heart's electrical pacemaker. It is a small patch of cells located in the wall of the right atrium; the frequency with which the SA node discharges electricity determines the rate at which the heart normally beats. The SA node keeps the heart beating in a regular manner.