Network protocols that use aggressive retransmissions to compensate for packet loss due to congestion can increase congestion, even after the initial load has been reduced to a level that would not normally have induced network congestion. Such networks exhibit two stable states under the same level of load.
Beta blocker. Beta blocker, also written Î²-blocker, is a class of medications that are particularly used to manage cardiac arrhythmias, and to protect the heart from a second heart attack (myocardial infarction) after a first heart attack (secondary prevention).
Certain medications can also cause first-degree heart block, including: 1  medications for treating abnormal heart rhythms (antiarrhythmics), such as disopyramide. 2  medications used to treat high blood pressure (hypertension), such as calcium channel blockers.  digoxin â a medication used to treat heart failure.