Do I have a case against a doctor who didn't aggressively treat my leaky heart valve?

If earlier intervention would have resulted in a materially different outcome, then you may have a medical malpractice case worth investigating. It sounds like what you learned after obtaining a second opinion suggests that more could have/should have been done, but the underlying assumption is that the valves were leaking when the first doctor was treating you. That is possible, but to know for sure an attorney will have to obtain the pertinent medical records and the results of any diagnostic studies that were performed on your heart.  If you want to investigate a malpractice case, you should contact a local medical malpractice attorney (one in your state).  They take these cases on a contingency basis which means you only have to pay if you succeed.  Additionally, initial consultations are usually free. You can use the "Find a Lawyer" service through this website to research medical malpractice attorneys.  Then, visit each attorney's website and look for a firm that has a record of successful verdicts.  Below are some articles you may find helpful.  They are written for a New Jersey audience (where I practice) but the ideas discussed in these articles usually apply in most other jurisdictions as well. Click here for an article that discusses the three main questions I ask when deciding whether to investigate a potential medical malpractice case. Click here for an article that explains what you can expect when filing a medical malpractice case. Click here and here for more information about me. Please note that by attempting to answer your question, I am not acting as your attorney. I will do nothing further to protect or preserve your interests in the absence of any additional discussion with you about this matter. John Ratkowitz, Esq. Starr, Gern, Davison & Rubin, P.C. 105 Eisenhower Parkway Roseland, NJ 07068 Office: (973) 830-8441 Cell: (732) 616-6278 Fax: (973) 226-0031 Email: jratkowitz@starrgern.com  Skype: john_ratkowitz Web: www.starrgern.com.