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Atrial Fibrillation at medium /high ventricular response_2

Short summary

72-year-old male had a TIA in 1995 and has been in chronic atrial fibrillation since 1992. In 2005 2 ablative procedures were ineffective. The main treatment strategy for his atrial fibrillation has consisted of rate control and oral anticoagulation. Despite several attempts of different medications (digoxin, beta-blockers) he has remained in atrial fibrillation with a relatively moderate to fast ventricular response.

Patient's questions
1)         What do you think is the best treatment to suggest between beta-blocker and digoxigenin? Alternative pharmacological options to these two ones? Are there indications for a further attempt of transcatheter ablation?
2)         In the light of the Holter test results in 2002, 2004 and 2008 do you notice a worsening in the arrhythmia? If so, is it correct to use a stronger antiarrhythmic drug?
3)         Do you think that the physical activity of the patient is consistent with his pathology taking into consideration that from a basic heart rate of 100 bpm it goes up, in a short time, to 150 bpm under stress? The patient can understand he has reached his effort limit from the dyspnea appearance or from the following breathless sensation?  
Medical Background
Patient's History
72 years old, male.
Diagnosis: Atrial Fibrillation at medium/high ventricular response
Medical history: 
-           In 1995 TIA (Transitory Ischemic Attack) which the MRI showed to be an ischemic lesion in the left parietal-temporal-occipital area.
-           Since 1992 AF (Atrial Fibrillation) for which in 2005 two ablations in Left Atrium (LA) were performed both being ineffective; at the Holter test in 2002 pauses longer than 2 seconds in the night-time (max 2,96 sec. at 2,50), in 2004 Holter without pauses. These examinations are being attached with the latest Holter test performed in November, 2008.
Case history:
During medical tests performed in October, 2007 the diagnosis of chronic AF (Atrial Fibrillation) with a slight biatrial dilation was confirmed; partial control of ventricular rate (often at around 100 bpm at rest, 150-160 under stress) with digoxigenin at low dosage (digoxinemia 0,5-0,6 with Lanoxil 0,250 mg/daily), patient always in a good hemodynamic compensation; patient on OAT (Oral anticoagulant therapy) with usual INR around 3; no evidence of ischemia in myocardial scintigraphy under stress in 2002.
At the end of these medical tests the two following pharmacological therapeutic options were suggested:
-           to continue taking digoxigenin, increasing its dosage: Lanoxin 0,250 1 tablet + Lanoxin 0,125 1 tablet, monitoring the digoxinemia at regular intervals;
-           to pass to a beta-blocker, for example Atenolol, starting with 100 mg ½ tablet in the morning, adding, if necessary ¼ tablet in the evening, proceeding, afterwards, with 100 mg in the morning, if the drug will be tolerated after about ten days.
The patient chose the second option replacing the therapy with digoxigenin with the beta-blocker and, at present, the home therapy consists of:
-           Lopresor 100 mg ½ tablet twice daily (at first atenolol that, however, was not well tolerated by the patient);
-           Sintrom according to INR.
Since the patient has started taking the beta-blocker, he has noticed a vertigo sensation with a slight progressive reduction of his physical performances.
At present, anyway, the patient practises a moderate physical activity playing tennis three times a week besides working out.
At present, the heart rate at rest is generally around 90-100 bpm, while after playing a tennis match it increases to 160-170 bpm.
To define the present clinical condition the results of recent medical reports of the latest performed cardiac medical tests are reported, the pictures of which you will find in the enclosure:
Holter test performed on 11/2008:
-       Total Arrhythmia due to Atrial Fibrillation throughout the all the RV media recording (91 bpm, min 49 bpm, max 150 bpm)
-       Present 1 pause longer than 2 seconds (2.22 sec at 09:57 a.m.)
-       Occasional isolated VEB (82), 1 couple
-       Stable the alterations of the ST-Segment
Color doppler echocardiography on 11/2008:
“Examination performed on patient in AF at medium/high ventricular response.
-       Regular left ventricular cavity dimensions (Telediastolic diameter=49mm; Telesistolic diameter=27 mm; Telediastolic volume=80ml) with slightly increased (=12mm) intraventricular septum end systolic thickness; no considerable alterations of the systolic thickening on the segments of the ventricular profile; uncompromised global systolic function (EF>60%).
-       Right ventricular cavity with normal dimensions and kinesis.
-       Minimal mitral valvular regurgitation.
-       Slight biatrial dilation (antero-posterior left atrial diameter = 46 mm).
-       Within normal limits the dimensions of the aortic root (=36 mm) and of the proximal segment of the ascending aorta”.
In the end it is reported that the patient has decided, by himself, to double since 1 week the therapy with Lopresor (passing from ½ tablet twice daily to 1 tablet twice daily) without any influence on the heart rate that remained unchanged.
Medical opinion
His basic problem is that his heart rate is still fast at rest at 90-100 rising to 150-160 with exercise. The lack of rate control is clearly the cause of any symptoms that he has with exercise. I do not think another attempt at cardioversion or pulmonary vein isolation/ablation would be effective. He needs to be on Coumadin therapy with an INR of 2-3 because of his previous TIA and also the LA size of 46.
In terms of rate control I would increase the digoxin dose to achieve a trough level of about 0.9 to 1.0. I would suggest increasing digoxin to .25 mg in the morning and .125 in the evening. After a week I would check a trough level in the morning before he takes his a.m. digoxin.
Once that level has been achieved I would add a nonselective beta-blocker with 24 hour duration, nadolol, probably at 40 mg twice a day or 80 in the morning depending on the heart rate. He may need 80 mg twice a day. The goal would be to achieve a heart rate of around 70 at rest and 110-120 with exercise. If the nadolol is effective one could reduce the digoxin back to .25 a day. A nonselective beta-blocker is much more effective in slowing the heart rate then a selective beta blocker and that is why I would use nadolol.
If the patient has unacceptable rate slowing or pauses on a beta-blocker in a dose that is necessary to keep him from having too fast heart rate I would put a permanent VVIR pacemaker in and set it at an escape rate of 60. This would allow you to use as much rate slowing drugs as you need to.
If he is intolerant of nadolol plus digoxin one could use a combination of digoxin plus verapamil or digoxin plus diltiazem. In general the combination of nadolol pulse digoxin is the most effective for rate slowing. I suspect his well being and physical activity will greatly benefit from adequate rate control as described above.