LV lead stimulating phrenic nerve

Last October I was involved in a head-on collision. I was shaken but seemingly okay and went to the ER to be physically examined. The triage nurse took my vitals and noticed my resting heart rate was 160. They rushed me into trauma and took EKG and reported I was experiencing SVT (supraventricular tachycardia) and that my readings also showed I had LBBB (left bundle branch block). They first attempted to treat the SVT by pushing drugs to pause my heart and try to coax it into a normal rhythm. When that failed, they administered electrocardioversion and shocked it into a normal rhythm. I was referred to a cardiologist and released that night. After running several tests including echocardio, and angiogram, I was diagnosed with severe non-ischemic dilated cardiomyopathy with extremely low EF (ejection fraction) of 18% and slight mitral regurgitation. During the angiogram procedure, the cardiologist was excited to point out my that my blood vessels were quite healthy and described them as "stove pipes". However, I was disappointed at that since if that was the cause (blocked arteries) it was an easy problem to fix with a stent. Unfortunately the angiogram only ruled out coronary artery disease, but didn't account for my symptoms. They immediately began a schedule of titration with metoprolol and lisinopril. Once the maintenance dosages were reached, I had another echocardio done. This time they measured EF twice - one at 18% again and the other at ~20%. The diagnosis was that I was at high risk for sudden cardiac death and that I should consider having a cardiac defibrillator implanted. My cardiologist felt that the LBBB was playing a significant role in the low EF; due to the fact that part of the normal electrical path was blocked, the circuit was rerouting and causing intraventricular conduction delays resulting in abnormal activation/contraction with dyssynchrony of the left and right ventricles. He prescribed the implantation of a CRT-D device (cardiac resynchronization therapy w/defibrillator). It's essentially a biventricular pacemaker with a defibrillator function. Typical defibrillators have a single lead. This device has 3 leads. One attached in the right atrium (actually screwed into the heart wall), one in the lower right ventricle and one in the posterolateral vein (outside of left ventricle). So that's what I had done for my birthday. I'm still sore and stiff from the surgery, but I feel a lot better with more energy than I've had in a long time. One annoying side effect is the left ventricle lead is right up against the phrenic nerve that controls the diaphragm and it's stimulating that nerve, causing my chest to thump and "pop" intermittently. Has anybody had experience with this? Did adjusting the device voltage resolve the issue? Prior to the car accident, I was experiencing tachycardias in my sleep and was waking up all sweaty which makes sense since my body was essentially running a marathon while I was asleep. In a way I was lucky to have had the car accident, since it was an opportunity to catch and treat this heart problem before it was too late.

3 Comments

Welcome To The PM Club

by SMITTY - 2011-06-18 02:06:07

Hello Dio,

That is quite a ride you had, but sounds like you are on your way to recovery.

I have had the phrenic nerve stimulation you are experiencing. I'm very familiar with the chest thumping, hiccups and the worst of all was there were times it felt like I was getting an electrical shock. I had lived with it for 2+ years with the Dr telling me it was not my PM causing my problem when I decided to hell with this and told the Dr to turn this thing off. I had gotten the PM for bradycardia which gave me a heart rate between 50 and 60. The Dr argued that I didn't know what I was asking for and he was correct, but enough was enough, so he did put the low set point so low that the PM never came on and my problem ceased.

A couple of years late another the Dr convinced me I should have the low setting increased to 60 or 70, and in a few days I had the phrenic nerve stimulation going again. However this the Dr knew what was going on and tried all sorts of PM settings changes to stop the problem. One that was tried was lowering the power output from the PM and that helped the phrenic nerve problem, but it had the PM essentially not doing anything again.

I was then given the options of living with the problem and hope it would got away, having the ventricle lead relocated or having the phrenic nerve deadened. Since the lead had by then been in place for over five years I really didn't want that and the deadening of the nerve sounded so easy. The nerve was deadened and it stopped the discomfort from the nerve stimulation completely. BUT, no one told me about the problems that could result from a deadened phrenic nerve.

I ended up with the right side of the diaphragm paralyzed. There was no immediate discomfort from the paralyzed diaphragm and the first thing I noticed that was not right was when I sat up in the bed the right side of my abdomen at the bottom of my rib cage would look like I had swallowed about half a basket ball. That brought on lots of tests and finally ended with a paper being written by some Drs on my experience.

Not too many months later I noticed I was getting extremely short of breath anytime I lean over, like to get something from the floor. A trip to a pulmonologist confirmed that the paralyzed diaphragm was allowing the internal organs to press on the bottom of my lungs and that was resulting in the SOB. There is a surgical procedure to try and take the slack out of the paralyzed diaphragm but at my age (82) and my experience with some other simple procedures that would do no harm, I decided to just limit my bending over and live with the problem.

I know this is long just to tell you, yes I have had a similar experience. Also I know I have become very cynical about my experiences with a PM. So the message I would convey to anyone that has a PM and are having problems remember "for every action there is a reaction." While the Dr may know the action, they do not always know the reaction, or, if they do they won't tell you.

Good luck to you,

Smitty

Just thinking

by ElectricFrank - 2011-06-19 01:06:44

Have you discussed the possibility of relocating the lead with the cardio? I've never heard of this, but there may be a way of electrically insulating the external lead from the nerve. With all the plastics that are compatible with the body there should be something that could be sutured in place to prevent electrical conduction.

You might need to do some research to find a cardio that is open to trying something unusual.

The electronic engineer in me is showing!

frank

Please explain

by kermiehiho - 2011-06-20 05:06:20

I ended up with a pacemaker for heart block after suffering heart contusion due a car accident, and I also experience some popping in my chest (usually near the sternum, but more on the left side). The popping generally happens right after I burp; I would guess three pops on average. The popping is not audible nor painful; I can only feel it in my chest. Is this what you mean by "pop"ping and "thump"ing? When I brought this up to my trauma doctor, he said it was probably either due to a broken rib from the accident that they didn't catch on the x-ray, or due to the fracture in my sternum (also due to the accident). If this is similar to what you're experiencing, though, I might have a chat with my cardiologist about it.

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