Mark Perrin

Cardiac Electrophysiology and Genetics

[Mark Perrin @epfellow]

@SergioPinski Adaptive CRT algorithm looking for intrinsic conduction. You often see this narrow QS in V1 instead of a strong R.

[John Dickson @johnpauldickson]

An early post-biblical explanation of the meaning of Jesus’ death (2nd-century AD).

[Mark Perrin @epfellow]

@xenux88 @JACCJournals @rbarvil @jpocardio @LRGuerr This is very interesting work. Congratulations. Could I ask: how do you know that the prognosis is not variant + background genetics specific, rather than gene specific. Presumably with such a high number of this variant in your location, there is some shared genetic background.

[Mark Perrin @epfellow]

@Hapa_EP https://t.co/sMrp8KoZcp

[Mark Perrin @epfellow]

@DrJasonAndrade AF or not, It will be fixed by the treatment used to fix AF! #PVI

[Prof John Lennox @ProfJohnLennox]

John's claim that Jesus is God culminates in this: the man who is God gave his life for each one of us.

That sense of value is something we cannot measure.

[Mark Perrin @epfellow]

@niall_gooch “ The sea is calm tonight. The tide is full, the moon lies fair Upon the strait”

[NPRG @CptHastings1916]

But also, of course, the classic text for election days: "Put not thy trust in princes, nor in the son of man, in whom there is no help. His breath goeth forth, he returneth to his earth." (Psalm 146).

[Prof John Lennox @ProfJohnLennox]

"Have you not known? Have you not heard? The Lord is the everlasting God, the Creator of the ends of the earth. He does not faint or grow weary; his understanding is unsearchable. He gives power to the faint, and to him who has no might he increases strength." - Isaiah 40:28-29

[Mark Perrin @epfellow]

@adamcifu Only if it was ironed.

[Mark Perrin @epfellow]

@SergioPinski Some more episodes, showing more typical TWOS, but one of which again shows strange noise on Can-Coil.

[Mark Perrin @epfellow]

Unusual noise on an ICD lead. Noise is seen on the farfield Can-RV Coil (lower), but not seen on the near-field RV Tip-Ring (upper), even though it seems to be sensing the noise. @jeffrey_vinocur @narrowQRS

[Mark Perrin @epfellow]

@SergioPinski Yes, positing a V sense (green arrow) and TWOS (red arrow) alternation fits. It is only the 150 ms FS (purple arrow) that does not. That, and the noise on the can-coil EGM.

[Mark Perrin @epfellow]

@SparkyDeviceRN @ecgrhythms @jeffrey_vinocur @narrowQRS No other issues. Multiple noise episodes. Not close to getting shocked.

[Mark Perrin @epfellow]

@SergioPinski @jeffrey_vinocur @narrowQRS That was the first thought but I double checked today and it was/is tip to ring.

[Jeffrey M Vinocur @jeffrey_vinocur]

@epfellow @narrowQRS @Medtronic I don’t love it. Although I don’t know if undersensing risk is different with R waves >20 and sensitivity 1.2 than R waves 5 and sensitivity 0.3?

Also we have low threshold for DFTs anyway because of complex hardware config and atypical patients and so may already have data

[JMC @narrowQRS]

@jeffrey_vinocur @epfellow @Medtronic One of the several arguments for the era of DFT testing, including VF induction with "least sensitive" sensing. Reassurance in the event that decreasing sensitivity in the future is needed for TWOS or phrenic myopotential oversensing.

[Mark Perrin @epfellow]

@narrowQRS @jeffrey_vinocur @Medtronic As a general question, how comfortable are you to reduce sensitivity in high voltage devices when other measures for TWOS fail?