Mental Exit Block

Atrial flutter with exit block.

The mechanism of atrial flutter is controversial. A 76-year-old woman with rheumatic heart disease was referred to our clinic with an unusual rhythm disturbance which initially appeared to be classic atrial flutter at a rate of 300 beats/min. Later tracings, however, demonstrated a rate exactly one-half that of the earlier ECGs, with an identical p-wave morphology and vector. This latter rhythm...

Paroxysmal atrial tachycardia with exit block.

Atrial tachysystole (flutter?) with apparent exit block.

A case of atrial tachysystole with apparent exit block is reported in which the basic cycle length of atrial activity is 260 msec. Simultaneous right intra-atrial electrograms show cycle lengths of 510 to 780 msec which are roughly multiples of 260 msec establishing the diagnosis of exit block. Rapid atrial stimulation (1,200/min) to overdrive the rapid ectopic atrial pacemaker was only transie...

On EXIT-Charts for Space-Time Block Codes

In this work, we consider the application of the well-known space-time block code (STBC), the Alamouti-scheme, as inner code within a “turbo” coding scheme for the multiple-input-multiple-output (MIMO) Rayleigh fading channel. We analyze therefore the applicability of the Alamouti-scheme for iterative space-time detection and decoding applied at the receiver. To this end, we use extrinsic infor...

Lessons from dissociated pulmonary vein potentials: entry block implies exit block

AIMS Prior reports using pacing manoeuvres, demonstrated an up to 42% prevalence of residual pulmonary vein to left atrium (PV-LA) exit conduction after apparent LA-PV entry block. We aimed to determine in a two-centre study the prevalence of residual PV-LA exit conduction in the presence of unambiguously proven entry block and without pacing manoeuvres. METHODS AND RESULTS Of 378 patients, 1...