The danger to the heart is believed to be from the immune response to the strep, not the infection directly.<p><a href="http:&#x2F;&#x2F;www.mayoclinic.org&#x2F;diseases-conditions&#x2F;rheumatic-fever&#x2F;basics&#x2F;causes&#x2F;con-20031399" rel="nofollow">http:&#x2F;&#x2F;www.mayoclinic.org&#x2F;diseases-conditions&#x2F;rheumatic-feve...</a>