Potassium helps maintain fluid balance and acts as a buffer in your blood. Potassium is also necessary for proper conduction of nerve impulses and muscle contraction. Because potassium controls muscles, it plays a vital role in your heartbeat. Abnormal levels of potassium in your blood can disrupt your heart.
Physiology
Your heartbeat is regulated by a tightly controlled electrical system. The electrical impulse that controls your heart begins in the sinoatrial, or SA, node. The SA node sends out an electrical current that signals the atria to contract. The electrical current then travels to a node called the atrioventricular, or AV, node. The AV node triggers the ventricles to contract. This electrical system ensures that the chambers of your heart beat in the proper succession so that blood can flow normally throughout your body. If your blood contains too much or too little potassium, it can disrupt this electrical system and cause abnormal heart rhythms that can lead to heart failure.
Potassium and Arrhythmias
In addition to being categorized as a mineral, potassium is also an electrolyte. Because it is an electrolyte, when potassium dissolves a solution it releases charged particles called ions. Normally, these ions help ensure that your nerve impulses travel correctly and your muscles contract. When potassium levels in the blood get too high or too low, the electrical conduction in your body becomes erratic. This abnormal electrical conduction disrupts the heart's electrical system and triggers abnormal heart muscle contractions. This combination can lead to abnormal heartbeats called arrhythmias. If arrhythmias are not properly controlled, they can put a great deal of strain on the heart, leading to heart failure.
Types of Arrhythmias
Abnormal blood potassium levels can lead to two major types of arrhythmias. Tachycardia refers to an abnormally fast heartbeat. Tachycardia is diagnosed when your resting heartbeat is greater than 100 beats per minute, according to MayoClinic.com. Bradycardia refers to an abnormally slow heartbeat. Bradycardia is diagnosed when your heartbeat is less than 60 beats per minute.
Treatment
To correct arrhythmias caused by too much or too little potassium in the blood and avoid heart failure, it is important to restore potassium levels back to normal. If your potassium levels are too high, a condition called hyperkalemia, you should avoid any supplements that contain potassium. If your blood potassium levels are too low, a condition called hypokalemia, you may need to increase your potassium intake.
It is also important to note that potassium levels can be disrupted by underlying medical conditions. If this is the case, it is important to figure out what your condition is and take steps to treat it.
Potassium Recommendations
Eating the proper amount of potassium each day can help reduce your risk of developing heart problems. The Food and Nutrition Board recommends that adults consume 4,700 mg of potassium daily. High potassium levels cannot be caused by excessive intake of potassium-rich foods but can occur as a result of excess supplementation. Avoid supplements that contain too much potassium.
References
- "Nutrition and You"; Joan Salge Blake; 2008
- Linus Pauling Institute: Potassium
- MayoClinic.com: Heart Arrhythmias
