I am looking for some advice regarding the differential diagnosis between ARVD and RVOT VT. I have always had episodes of palpitations, which tend to come and go periodically, lasting for a few weeks then disappearing for months. Arrhythmic triggers seem to be running, post running/recovery, stress, and lower heart rates at night while lying down. There are other times when it just seems to happen with no apparent trigger. I also have much less frequent lightheaded spells that may or may not be related, along with chronic fatigue despite being a young, healthy runner.
This past spring and early summer I had a bunch of cardiac workup completed. I had 2 echos, a regular stress test, a QT interval stress test, about 8 different EKG’s, a 24 hour Holter monitor, a 48 hour Holter, and a 30 day event monitor. Short of some sinus pauses while sleeping, along with some fairly infrequent ectopic beats (about 15-20/day, but most of which I apparently feel) there was nothing of note, although these tests were all completed when I was generally asymptomatic. I have seen my general doctor, an interventional cardiologist, an electrophysiologist, and a second electrophysiologist who specializes in LQT and Brugada.
As a result of these tests they have been able to rule out all structural causes of arrhythmias (which make up 90% of cases, at least for ventricular arrhythmias), and all channelopathy and additional primary electrical diseases (i.e. Long QT Syndrome, Brugada Syndrome, CPVT, Short QT Syndrome, Malignant Early Repolarization Syndrome). In the absence of structural or electrical/channelopathy disease as an option for the origin of my arrhythmias they have deemed them to be idiopathic-benign arrhythmias.
The only thing that does still concern me is the fact that at least concerning the documented PVC’s (along with what I strongly suspect to have been undocumented cases of NSVT in the past) is that 85% of all idiopathic-benign ventricular arrhythmias originate from the RVOT (right ventricular outflow tract). The RVOT is also a point of origin for ARVD (Arrhythmic Right Ventricular Dysplasia), and RVOT PVC’s and NSVT or even monomorphic sustained VT can be early symptoms of this far more malignant disease process, in spite of the symptoms itself holding a benign nature.
Now, I have the following mapped out as some evidence that this really is idiopathic PVC’s, not early “concealed” ARVD:
-No family history of cardiac arrest at young ages or any age (the disease is genetic)
-Regular size and function for the right ventricle on both echos.
-No history of syncope or near syncope despite probably unrelated occasional lightheadedness not associated with exercise.
-BNP level was normal at 7, so no ventricular wall strain is shown, and studies have connected elevated BNP to ARVD but not benign RVOT arrhythmias.
-C-Reactive Protein level was normal at 0.3, so no systemic inflammation which studies have associated with ARVD.
-EKG does not demonstrate epsilon waves nor inverted T waves in V1-V3 (inverted in V1, but that is normal variant, positive T-waves in V2-V3)
However, there is some vague evidence that could be used to suggest the possibility of looking further into ARVD:
-I am 25% Italian and much like Brugada and Asians, ARVD is heavily associated with Italians.
-I am only 21 and early ARVD may not have progressed enough to be detectable by echo and EKG.
-Palpitations started around age 13-14, and that is around time ARVD symptoms might begin (although also the time when IVLT and RVOT PVC/VT begins)
-I am male and it is more predominant in males.
-I am an athlete and athlete’s who hold genetic predisposition to ARVD may activate that gene expression quicker and more profoundly than sedentary people due to persistently high nitric oxide in the blood.
-My QRS axis is consistently between 80 and 90 degrees which is a little right pointing and may be indicative of near-right ventricular hypertrophy which would be present if the RV was becoming dilated from fatty infiltration in ARVD.
-Leads III and V1 have inverted T-waves and lead III is furthest right pointing limb lead and V1 is furthest right pointing chest lead, which may show right ventricular wall strain.
-It appears I may have an S1Q3T3 pattern, which is indicative of some degree of RV strain, which could be seen in ARVD.
Given this, I’m looking for opinions as to whether or not a clean echo, low blood markers of cardiac inflammation and wall strain, as well as the lack of passing out, lack of family history, and EKG generally clear of major markers of ARVD is sufficient enough for me to comfortably rule this out and obtain peace of mind that I have benign-idiopathic arrhythmias or do you think some of the vague findings on my EKG’s, coupled with my palpitation history and being a young athletic male should be enough to warrant me to insist upon a cardiac MRI to further validate the claim that I do not have ARVD?