The patient was a 38 year-old healthy male without a history of cardiovascular or psychiatric disease who experienced a sudden collapse while bicycling to work. On primary assessment by paramedics he was found to be pulseless. Cardiopulmonary resuscitation was initiated. He was electrically cardioverted, resuscitated, and rushed to the nearest hospital. To preserve cerebral function, the patient was placed in an induced hypothermic and comatose state. During his recovery he experienced an episode of ICU delirium with agitation resulting in administration of sedative medication. After recovering from this delirium, he reported discrete retrograde memory loss from 1 day prior to the event through the first week after his SCA. He underwent ICD implantation (dual lead, atrial and ventricular, Medtronic Inc. St Paul, MN) at 2 weeks for secondary prevention of sudden death, and was discharged from the hospital shortly afterwards. He returned to work 3 weeks after the event. Immediately after ICD implantation the patient described being very fearful of being alone in the house with his young children. In response, he and his wife developed procedures to ensure that their children knew how to call emergency medical services if he were to become unresponsive or be shocked.
The patient experienced his first ICD shock 11 months later, while riding the exercise bike at a local gym. He received a total of 6 shocks over approximately 2-3 min. After realizing he was being shocked, he did not recall experiencing anxiety. Rather, he described responding calmly and without terror, in a way that did not distract or alert others to his experience (i.e., no social disruption). In the patient's words: "they had told me it would feel like getting kicked in the chest by a horse. It didn't really feel like that. It was just a very loud, like a 'thunk!' sound. I maintained consciousness. At first I wasn't sure what it was. By the time the second one came, I realized this must be the defibrillator going off. And I was conscious the whole time, and walking. I don't know what the interval was, probably I guess 15-20 seconds in between [each shock]." Patient's wife: "you weren't very fazed by it though, and nobody else knew what was happening." Patient: "Right. And that goes to some of my anxiety, and why some of the subsequent shockings impacted me more than that one. This one I was able to keep private. Nobody knew what was happening. I knew I got shocked. I went home, called my doctor. It wasn't a very big public scene."
The patient experienced his second episode of repeated ICD shocks while at the gym, after 15 min of jogging on the treadmill. He received a total of 7 shocks approximately 20 s apart. He again denied experiencing any social disruption, but this time felt terror over the lack of control over his symptoms. He also described experiencing physical pain with the shock. In the patient's words: "It's not so much the pain of the shock as much as, is there another one coming? Is this the last one, or am I bracing for another one? I'm trying to calm down, to get my heart rate down, but it's almost impossible because I'm under this utter terror that another one is coming, and another one, and is it ever going to stop?"
During this second set of shocks, despite the reported fear and aversive anticipation of subsequent shock, he denied experiencing thoughts of death. When asked how he considered the meaning of the shocks, he stated "I'm not afraid I'm going to die, I don't feel like this event is going to kill me. At that time I'm more concerned with 'will it stop? How can I make it stop, and who is going to help me make it stop?' I feel somewhat powerless in this whole sequence of being subjected to these shocks, with really no ability to make it stop at some point. That's what impacts me most when it's happening." He further noted: "When I got my defibrillator originally, I remember this distinctly, my doctor told me 'You're gonna die some day. But it's not going to be from this. You've got the defibrillator now, you're not going to die from this.' And I certainly took some comfort from that."
After uploading data from the ICD to his cardiologist, which demonstrated a ventricular tachycardia progressing to ventricular fibrillation, he was referred for further treatment via cardiac catheter ablation procedure to target a focus of premature ventricular contractions (PVCs) that had been previously identified. He also underwent an atrial lead revision and generator change during a separate procedure.
After the second set of shocks, the patient became preoccupied with the potential impact the shocks might have on his social milieu, a fear that "I'm gonna get shocked in front of other people and they will think I'm defective." He developed several avoidance behaviors. He stopped exercising or engaging in all activities that could potentially increase his heart rate (including sex), under the belief that this would cause him to experience another shock. Hypervigilance emerged: he began scanning his body for signals that could predict a shock, such as feeling a fast heartbeat, or a "not good" feeling. He began to seek further reassurance that he was unlikely to receive another shock, by frequently contacting his cardiologist and frequently monitoring his ICD's electronic output. During each of these visits, no abnormalities were found.
Two and a half years after receiving his first shock, the patient reported being shocked "in a different way." While out of town and walking with some co-workers, he received a shock and fell to the ground, grunting and groaning. There was no loss of consciousness. He continued to receive a total of 8 shocks in a row. Paramedics arrived at the scene and administered anxiolytic benzodiazepines, which the patient believes aborted the shocks. He was hospitalized for 4 days. Interrogation of his ICD revealed he had received appropriate ICD discharges in response to the spontaneous development of ventricular tachycardia. There were no further abnormal findings on electrophysiological exam, and he was discharged without application of any specific procedures or medications. This experience affected the patient differently, because "I could no longer hide it. There's shame involved, [that] there's something wrong with me." The lack of specific treatments rendered further anxiety. Riding home alone on the airplane he was extremely anxious about being shocked again, without access to emergency medical services. He experienced his first panic attack in midair, with prominent dyspnea, palpitations, dizziness, and fear of losing control over his mind and body. He also worried that being shocked in front of other people would cause them to think he was defective. After arriving home safely, he began to experienced recurrent panic attacks, approximately 10-15 times per month. These were often provoked when in open or crowded spaces, and so he began avoiding them. He began to avoid conversations while walking, "because that's what I was doing when I got shocked." He also experienced several spontaneous attacks without a clear trigger.
Due to continued distress from these symptoms, the patient established his first contact with a mental health provider 3 years and 9 months after receiving his first shock. He began counseling treatment with a licensed clinical social worker, every 2 weeks, for a total of 6 visits. He learned basic relaxation techniques including deep abdominal breathing. Other elements of the treatment, in the patient's words included: "He told me how to deal with the shame of the event, by telling people around me what could happen, what they should do. He told me that if I told more people about it, I wouldn't be as concerned about the public spectacle." The patient did not receive any psychiatric evaluation or other forms of treatment.
A week and half prior to psychiatric evaluation at UCLA, and nearly 4 years after his initial SCA, the patient received his fifth set of ICD shocks while at work. During a meeting he had a "premonition" and began to feel anxious about being shocked. He began to feel "not good," felt his heart beating faster and "I knew that a shock was coming." After receiving his third shock, he told a coworker to call emergency medical services. He received a series of 13 shocks over a period of minutes. He recalls that when the paramedics arrived and administered IV lorazepam, the shocks seemed to stop. He was again hospitalized for medical evaluation. According to his wife, he would often receive intravenous lorazepam for anxiety, particularly prior to his physicians' arrival for morning rounds, and was discharged with a prescription to take this on an as needed basis.
Based on the pattern of recurrent ICD shocks, the patient was referred by his cardiologist for consideration for BCSD at UCLA. He underwent this procedure the day after his psychiatric evaluation.
In addition to experiencing SCA, the patient had been diagnosed with a polymorphic ventricular tachycardia, undergone a dual lead ICD implantation. Surgical procedures included cardiac catheter ablation for PVCs, atrial lead and generator replacement, right shoulder dislocation with subsequent shoulder surgery, and appendectomy.
The patient received a bachelor's degree in computer engineering and was currently employed as an engineer in a hardware design firm. There was no history of developmental disabilities. He was married, with two children. He denied any history of abuse or arrests. In reference to his early social life, he described himself as an "awkward teenager," whose friendships were mainly with "outcast kids." The patient reported a brief period of marijuana use in college, but otherwise denied any regular alcohol, tobacco or illicit substance use. Family history was notable for a myocardial infarction (paternal grandfather), and alcohol dependence (uncle). There was no other family history of psychiatric illness, and no family history of suicide.
At the initial evaluation, the patient was prescribed the following medications: lorazepam 1mg BID prn (patient reported using 2 mg BID for the prior 10 days), metoprolol 10 mg BID, verapamil 120 mg BID, and aspirin 81 mg daily.
After undergoing a structured clinical interview utilizing MINI International Neuropsychiatric Interview (Sheehan et al.,), the patient met DSM IV-TR diagnostic criteria for Post-Traumatic Stress Disorder, Panic Disorder with Agoraphobia, and Social Anxiety Disorder. There was no evidence of axis II pathology. Symptom severity was assessed using several quantitative clinical measures. These indicated "severe" levels of general anxiety (via Beck Anxiety Inventory, BAI (Beck and Steer,), "markedly ill" levels of panic (via Panic Disorder Severity Scale, PDSS) (Furukawa et al.,), and borderline clinical depression (via Beck Depression Inventory, BDI) (Beck and Steer,) (Table 1).
In an attempt to reduce susceptibility to recurrent ventricular tachycardia, partial sympathectomy via BCSD has been applied in selected treatment refractory patients at UCLA (Ajijola and Shivkumar,; Ajijola et al.,; Vaseghi et al.,). Bilateral cardiac sympathetic lesioning decreases sympathetic efferent noradrenergic innervation to the heart, and putatively mitigates the pro-arrhythmic effects of sympathetic innervation (Ajijola et al.,). The patient underwent this procedure, consisting of a resection covering the lower half of the stellate ganglion and the bodies of sympathetic chain from T2 through T4. He has been followed for approximately 1 year.
Immediately after recovering from the surgery, the patient reported continued episodes of anxiety, including one nocturnal panic attack. He continued utilizing lorazepam 2 mg daily as needed for anxiety, but during these episodes noted "I couldn't feel my heart racing." After 2 weeks, he continued experiencing anxiety that "comes and goes." He was still using lorazepam as needed, approximately every 2-3 days. He had not experienced any further panic attacks.
After 1 month, the patient had returned to work and reported "I'm starting to feel better." However, he avoided his first work meeting by calling in from home, and still endorsed "a lot of anxiety" related to being in situations where he had been shocked previously, including work. When he did eventually attend a work meeting with a colleague, he denied experiencing anticipatory sensations as before, including the absence of a rapid pulse, causing the patient to spontaneously note "I have noticed differences in how my body reacts." When referring back to his home vital sign monitoring records, he reported that his average heart rate had decreased from the 80's to 65. Quantitative examination of his psychiatric symptoms at this time compared to prior to BCSD revealed an unchanged level of general anxiety (via BAI) and slightly decreased intensity of panic (via PDSS) (Figure 1). Based on these continued symptoms, he was referred for cognitive behavioral therapy (CBT) with a PhD psychologist specializing in treatment of PTSD.
At 1 month he reported experiencing a single atypical shock. In the patient's words: "when leaving work today I was fixing something on the floor. When I stood back up I did not feel right. Not dizzy just felt that something was not right. I took a sip of water to try and calm myself but the feeling did not go away. I walked downstairs and the sensation got stronger. Then I got a single shock. Seemed more mild than others. After the shock I had a real difficult time calming my body down as with prior incidents. Despite this I did not receive a cascade of shocks. Perhaps the benefit of the procedure:stopping my body reaction from impacting the ability of the heart to return to normal rhythm. Despite my panic, I only received a single shock. In the past my inability to calm myself down would result in multiple shocks usually until EMS arrived and administered a calming medication." Analysis of his ICD data showed a fast ventricular tachycardia that was different from previously observed ventricular fibrillation. It was felt that this could be due to post-lesion cardiac remodeling. He was started on amiodarone 200 mg BID.
Three months after undergoing BCSD, the patient reported he was "doing better." He was receiving weekly psychotherapy via CBT and had completed 8 sessions. He was learning "more awareness of what anxiety is and what a panic attack is." He was also learning different strategies to cope with and manage his anxiety, including advanced deep breathing techniques and guided pre-recorded audio meditations. He had not started exposure and response prevention, a common and effective behavioral component of CBT, but had begun discussing this approach with his therapist. He reported experiencing continued panic attacks 1-2 per week, but felt these were less severe, and of shorter duration (1-2 min in duration vs. 10 min). In addition, he continued to note "I don't feel my heart rate like I did during anticipation of shock. I also don't feel PVCs as much as I used to." Although he reported walking more, he was still avoiding most meetings by calling in sick, and avoiding going to the gym. Due to his continued symptoms he had been referred to a psychiatrist, had been prescribed a low dose of an SSRI, sertraline, initially 12.5 mg daily and up to 25 mg daily at the time of contact. He continued taking lorazepam on an as-needed basis, but at a lower dose of 1 mg daily three to four times per week. Quantitative review of his symptoms now demonstrated a nearly 50% drop in general anxiety down to a 'mild' level (via BAI), a continued decrease in panic severity (via PDSS), and a small but clinically insignificant decrease in depression (via BDI; Figure 1). He had not experienced any further shocks, and no further ICD events were detected.
Six months after undergoing BCSD, the patient continued receiving weekly psychotherapy. He had begun conducting prolonged exposures, a common treatment for psychotherapeutic treatment of PTSD, tailored toward the experience of being shocked. These pertained to "the memories of the two most significant shock events that have been very difficult for me to think or talk about. I discuss the memory in detail and record it on my phone and then listen to the recording multiple times. It has helped a lot and I no longer have a significant reaction to thinking about those memories." He stated he was no longer avoiding going to the gym, and was no longer avoiding individual meetings at work. He continued to express concern about attending group meetings. Sertraline had been increased to 150 mg daily. He noted difficulty "to differentiate the benefits of the sertraline and [psychotherapy]." He had not experienced any further shocks, and no further ICD events were detected. In reviewing his progress, he spontaneously noted, "all in all, I have improved significantly from last fall and I can see a day when I will return to my prior self." Quantitative review of his symptoms now demonstrated a nearly 50% drop in general anxiety (via BAI) and a continued decrease in panic severity (via PDSS), with a small but clinically insignificant increase in depression (via BDI; Figure 1).
Nine months after undergoing BCSD, the patient reported "I have been feeling a lot better lately." He continued seeing his therapist but on a slightly decreased basis, weekly to bimonthly. His sertraline had been increased to 200 mg daily. He continued to refrain from utilizing lorazepam. He had not experienced any further shocks, and no further ICD events were detected. Quantitative symptom review revealed that most of the patient's symptoms had continued declining. His general anxiety level was in the "very low" range, and symptoms of panic were now in the "borderline ill" range (Furukawa et al.,). His depression was now in the non-clinical range of "normal ups and downs."
The patient summarized his progress at 9 months as follows: "At times not even thinking about my condition. Previously, it was a constant thought - constant polling of my body to make sure I felt ok. There have been days where I have felt completely normal. I'm now getting active again. Starting on the treadmill. A remaining fear is associated with activity and getting my heart rate up. Breathing hard is especially a trigger that I have avoided. The difference now is that I no longer view getting on the treadmill as impossible. I feel like I can do it:gradually. Feeling better in social situations also. Had an impromptu lunch with two colleagues last week. Felt good for the entire lunch and participated in conversation and started some conversations. Previously, I had avoided this type of situation. I did have one episode yesterday that caught me off guard. At the end of a meeting we were talking about general things. We were talking about injuries and one person mentioned my SCA [Sudden Cardiac Arrest]. Everyone there knew about my history but one. I have talked about it recently without issue. However, after I started telling the story of my original SCA I had a very strong sensation:rushing feeling like someone is cranking up the volume inside my body. I tensed up expecting a shock. No shock occurred but I got up and returned to my desk and relaxed to decrease my pulse rate."
1 year after undergoing BCSD the patient's anxiety, panic and depression symptoms remained markedly attenuated, and in non-clinical ranges (Figure 1). He continued psychotherapy at a further decreased frequency, once per month, and anticipated discontinuing this soon afterwards. He continued on an unchanged dose of sertraline, 200 mg daily. He no was no longer utilizing lorazapam. Other medications included verapamil 120 mg BID, metoprolol 50 mg daily, and aspirin 81 mg daily. His cardiologist had tapered and discontinued amiodarone 1 week before. He had not experienced any further shocks. Review of his ICD data showed no events over the past 6 months, which was the "first time that has ever happened since my initial arrest." This information was particularly "surprising," as this objective record failed to corroborate the subjective diary records of the exact dates and times when he had perceived the body sensations of an abnormal event during that time period.
In subjectively reviewing his symptoms 1 year after BCSD, the patient noted "I'm starting to have days were I do not constantly think about whether a shock is imminent. I no longer struggle and avoid social situations." He noted the lingering presence of cognitive threat appraisals: "I do still encounter thoughts of playing out scenarios of what would happen if my defibrillator went off:who would see, what would happen. This happens when I'm in social situations especially when walking. I do very occasionally have episodes of what I call an 'attack.' Basically, having a physical sensation that mimics the feeling that I get right before a shock. It is like a rushing feeling:tensing up in my body:bracing for the shock. When that happens I usually quickly excuse myself from the situation and calm down and the 'attack' passes."
He reported further decreased avoidance of exercise: "I have started walking on the treadmill on a regular basis. Fast walking. Enough to sweat:about 40 min. However, I make a conscious effort to control my breathing and not let my pulse rate get elevated." Despite his increased exercise capacity, at 1 year the patient reported he had sustained a 50 pound weight gain. He also endorsed continued preoccupation with receiving a shock during physical exertion: "The one remaining aspect of my treatment is dealing with my fear of activity. I'm terrified that elevating my heart rate will result in a shock. Frankly, I don't think I will ever move past this fear. The times I have been shocked my pulse has been high. The procedure effectively lowered my pulse rate. So logic leads me to thinking that if the procedure lowers my heart rate then why would I increase it purposefully." Exactly 1 year after his worst shock episode, these preoccupations were reflected by moderately elevated scores on the SCS and FSAS, and clinically significant scoring on the PCL (Figure 1).
The patient did not experience Horner's Syndrome, an occasional occurrence with stellate ganglion nerve blocks (Schurmann et al.,; Lipov,). This was due to the selectivity of the patient's lesion, which spared the caudal head of the stellate ganglion, a region carrying sympathetic nerve fibers to the eye and face. The patient did report the subsequent absence of sweating of the palms and head, and development of hyperhidrosis of the trunk and legs, which have been described as compensatory responses to the severing of sympathetic nerve fibers to the trunk (Hashmonai et al.,; Drott et al.,).
Subscale examination of the patient's anxiety revealed several notable patterns (Figure 2, Table 2). During the 2 weeks after undergoing BCSD, the patient reported an overall increase in feeling bothered by several cognitive and interoceptive components of anxiety. The former may have been related to uncertainty about receiving future shocks, and concern about the successfulness of the surgery. The latter may have been related to post-lesion remodeling within the autonomic nervous system that can result in the symptoms of heat sensations, flushing and difficulty breathing reported by the patient. Despite these increases, the patient reported decreases in feeling bothered by dizziness and lightheadedness, and a reduction in feeling bothered by the experience of his heart pounding and racing (Figure 3). Both of these decreases appeared clinically significant, i.e., the symptoms decreased from the maximum score ("severely:it bothered me a lot") to a mild score ("mildly but it didn't bother me much"). Furthermore, these reductions were sustained throughout the year. In the case of heartbeat sensations, at 1 year the patient reported a complete cessation of symptoms (Figure 3). The only other symptom that declined with a similar magnitude was the feeling of being scared, which decreased entirely between 2 weeks and 3 months after the procedure. Of note, this timeframe corresponded to the initiation of CBT, and formation of a therapeutic bond with his psychologist. It seems unlikely this drop was due to pharmacotherapy, as the patient was no longer utilizing benzodiazepines at that time and had only recently initiated a subtherapeutic dose of sertraline (25 mg daily).
The patient also demonstrated a decline in shock related catastrophic thinking (via SCS) between 6 and 9 months post-lesion. This timeframe corresponded to completion of the majority of his CBT visits, and also to the titration of sertraline to a therapeutic dose. Given the concomitant nature of both interventions, is therefore difficult to distinguish which was more likely responsible for the decrease in catastrophizing symptoms during that timeframe.
With regard to symptoms of PTSD assessed via PCL, the patient demonstrated low-moderate scores between 3 and 9 months, which were in the non-symptomatic range via scoring criterion 2 (Blanchard et al.,). Exactly 1 year after the patient's last episode of ICD shock storm, the patient's PCL score increased into the symptomatic range. Similarly, at 1 year the patient's score on the FSAS was in the moderate range. Subsequent inquiry revealed that the patient was quite aware of this epoch, and had been thinking about his last shock episode during the days and weeks leading up to this anniversary event. He also explained that he had recently began pushing the limits of his exercise comfort level as a part of his exposure and response prevention psychotherapy, which is known to temporarily increase anxiety levels (Craske and Barlow,). It is possible that his FSAS score could have been decreased (or elevated) prior to this time period, but this remains speculative as this data was unavailable for earlier time points.