Inter-beat (RR) Intervals. The time intervals between consecutive heart beats are customarily measured in the electrocardiogram from the beginning of a QRS complex to the beginning of the next QRS complex, so these intervals might be called QQ intervals, but they are conventionally named RR intervals.
Dubuque County, Iowa. Dubuque County is a county located in the U.S. state of Iowa. As of the 2010 census, the population was 93,653. The county seat is Dubuque. The county is named for Julien Dubuque, the first European settler of Iowa. Dubuque County comprises the Dubuque, IA Metropolitan Statistical Area, and is the seventh largest county by population in the state.
In 1882 the name of the county was renamed to Webster in honor of Daniel Webster. The county seat of Webster County is Walthall. Webster County is located approximately 28 miles east of Interstate 55 and 48 miles west of the Tennessee Tombigbee ports in Lowndes County. Webster County has a total area of 423 square miles of which 2.3 square miles is water.