Final answer:
True, myocardial ischemia can lead to the occurrence of Premature Junctional Contractions (PJCs) due to the increased irritability of the heart's electrical system caused by reduced blood flow.
Step-by-step explanation:
Myocardial ischemia occurs when there is a reduction in blood flow to a part of the heart muscle, usually due to a blockage in one or more of the coronary arteries. This blockage is most often caused by atherosclerosis, where plaque buildup narrows the arteries, sometimes leading to the formation of blood clots that can further obstruct blood flow.
Ischemia can result in various changes to the heart's electrical activity. Specifically, it can increase irritability within the heart muscle, leading to premature contractions. These premature beats can originate from the ventricles (PVCs), atria (PACs), or the junctional tissues (PJCs). A Premature Junctional Contraction is an early heartbeat that starts in the part of the heart called the atrioventricular node (the junction between the atria and ventricles), rather than starting in the sinoatrial node and traveling through the atria to the ventricles.
When myocardial ischemia occurs, it can disturb the normal rhythm of the heart and trigger PJCs due to the increased irritability of the cardiac tissues. Although PJCs themselves may not be life-threatening, they are often a sign of underlying heart disease and can be symptomatic of more serious conditions such as ischemia. The presence of PJCs may also indicate an increased risk of other arrhythmias which, depending on their nature and frequency, might require medical attention.
The key point is that the relationship between myocardial ischemia and arrhythmias like PJCs underscores the importance of maintaining heart health and addressing any potential cardiovascular issues promptly.